Changeset 39727

Timestamp:

01/06/2017 05:53:59 AM (8 years ago)

Author:

dd32

Message:

Mail: Upgrade PHPMailer to 5.2.21.

Merges [39645], [36083], [33142], [33124] to the 4.1 branch.
See #37210.

Location:

branches/4.1

Files:

• . (modified) (1 prop)
• src/wp-includes/class-phpmailer.php (modified) (201 diffs)
• src/wp-includes/class-smtp.php (modified) (42 diffs)

branches/4.1/src/wp-includes/class-phpmailer.php

@@ -2 +2 @@
 /**
  * PHPMailer - PHP email creation and transport class.
- * PHP Version 5.0.0
- * Version 5.2.7
+ * PHP Version 5
  * @package PHPMailer
- * @link https://github.com/PHPMailer/PHPMailer/
- * @author Marcus Bointon (coolbru) <phpmailer@synchromedia.co.uk>
+ * @link https://github.com/PHPMailer/PHPMailer/ The PHPMailer GitHub project
+ * @author Marcus Bointon (Synchro/coolbru) <phpmailer@synchromedia.co.uk>
  * @author Jim Jagielski (jimjag) <jimjag@gmail.com>
  * @author Andy Prevost (codeworxtech) <codeworxtech@users.sourceforge.net>
  * @author Brent R. Matzelle (original founder)
- * @copyright 2013 Marcus Bointon
+ * @copyright 2012 - 2014 Marcus Bointon
  * @copyright 2010 - 2012 Jim Jagielski
  * @copyright 2004 - 2009 Andy Prevost
@@ -19 +18 @@
  */
 
-if (version_compare(PHP_VERSION, '5.0.0', '<')) {
-    exit("Sorry, PHPMailer will only run on PHP version 5 or greater!\n");
-}
-
 /**
  * PHPMailer - PHP email creation and transport class.
- * PHP Version 5.0.0
  * @package PHPMailer
- * @author Marcus Bointon (coolbru) <phpmailer@synchromedia.co.uk>
+ * @author Marcus Bointon (Synchro/coolbru) <phpmailer@synchromedia.co.uk>
  * @author Jim Jagielski (jimjag) <jimjag@gmail.com>
  * @author Andy Prevost (codeworxtech) <codeworxtech@users.sourceforge.net>
  * @author Brent R. Matzelle (original founder)
- * @copyright 2013 Marcus Bointon
- * @copyright 2010 - 2012 Jim Jagielski
- * @copyright 2004 - 2009 Andy Prevost
  */
 class PHPMailer
@@ -39 +30 @@
     /**
      * The PHPMailer Version number.
-     * @type string
-     */
-    public $Version = '5.2.7';
+     * @var string
+     */
+    public $Version = '5.2.21';
 
     /**
      * Email priority.
-     * Options: 1 = High, 3 = Normal, 5 = low.
-     * @type int
-     */
-    public $Priority = 3;
+     * Options: null (default), 1 = High, 3 = Normal, 5 = low.
+     * When null, the header is not set at all.
+     * @var integer
+     */
+    public $Priority = null;
 
     /**
      * The character set of the message.
-     * @type string
+     * @var string
      */
     public $CharSet = 'iso-8859-1';
@@ -58 +50 @@
     /**
      * The MIME Content-type of the message.
-     * @type string
+     * @var string
      */
     public $ContentType = 'text/plain';
@@ -65 +57 @@
      * The message encoding.
      * Options: "8bit", "7bit", "binary", "base64", and "quoted-printable".
-     * @type string
+     * @var string
      */
     public $Encoding = '8bit';
@@ -71 +63 @@
     /**
      * Holds the most recent mailer error message.
-     * @type string
+     * @var string
      */
     public $ErrorInfo = '';
@@ -77 +69 @@
     /**
      * The From email address for the message.
-     * @type string
+     * @var string
      */
     public $From = 'root@localhost';
@@ -83 +75 @@
     /**
      * The From name of the message.
-     * @type string
+     * @var string
      */
     public $FromName = 'Root User';
@@ -90 +82 @@
      * The Sender email (Return-Path) of the message.
      * If not empty, will be sent via -f to sendmail or as 'MAIL FROM' in smtp mode.
-     * @type string
+     * @var string
      */
     public $Sender = '';
@@ -97 +89 @@
      * The Return-Path of the message.
      * If empty, it will be set to either From or Sender.
-     * @type string
+     * @var string
+     * @deprecated Email senders should never set a return-path header;
+     * it's the receiver's job (RFC5321 section 4.4), so this no longer does anything.
+     * @link https://tools.ietf.org/html/rfc5321#section-4.4 RFC5321 reference
      */
     public $ReturnPath = '';
@@ -103 +98 @@
     /**
      * The Subject of the message.
-     * @type string
+     * @var string
      */
     public $Subject = '';
@@ -110 +105 @@
      * An HTML or plain text message body.
      * If HTML then call isHTML(true).
-     * @type string
+     * @var string
      */
     public $Body = '';
@@ -119 +114 @@
      * capability such as mutt & Eudora.
      * Clients that can read HTML will view the normal Body.
-     * @type string
+     * @var string
      */
     public $AltBody = '';
@@ -129 +124 @@
      * @link http://sprain.ch/blog/downloads/php-class-easypeasyics-create-ical-files-with-php/
      * @link http://kigkonsult.se/iCalcreator/
-     * @type string
+     * @var string
      */
     public $Ical = '';
@@ -136 +131 @@
      * The complete compiled MIME message body.
      * @access protected
-     * @type string
+     * @var string
      */
     protected $MIMEBody = '';
@@ -142 +137 @@
     /**
      * The complete compiled MIME message headers.
-     * @type string
+     * @var string
      * @access protected
      */
@@ -149 +144 @@
     /**
      * Extra headers that createHeader() doesn't fold in.
-     * @type string
+     * @var string
      * @access protected
      */
@@ -156 +151 @@
     /**
      * Word-wrap the message body to this number of chars.
-     * @type int
+     * Set to 0 to not wrap. A useful value here is 78, for RFC2822 section 2.1.1 compliance.
+     * @var integer
      */
     public $WordWrap = 0;
@@ -163 +159 @@
      * Which method to use to send mail.
      * Options: "mail", "sendmail", or "smtp".
-     * @type string
+     * @var string
      */
     public $Mailer = 'mail';
@@ -169 +165 @@
     /**
      * The path to the sendmail program.
-     * @type string
+     * @var string
      */
     public $Sendmail = '/usr/sbin/sendmail';
@@ -176 +172 @@
      * Whether mail() uses a fully sendmail-compatible MTA.
      * One which supports sendmail's "-oi -f" options.
-     * @type bool
+     * @var boolean
      */
     public $UseSendmailOptions = true;
@@ -183 +179 @@
      * Path to PHPMailer plugins.
      * Useful if the SMTP class is not in the PHP include path.
-     * @type string
+     * @var string
      * @deprecated Should not be needed now there is an autoloader.
      */
@@ -189 +185 @@
 
     /**
-     * The email address that a reading confirmation should be sent to.
-     * @type string
+     * The email address that a reading confirmation should be sent to, also known as read receipt.
+     * @var string
      */
     public $ConfirmReadingTo = '';
 
     /**
-     * The hostname to use in Message-Id and Received headers
-     * and as default HELO string.
-     * If empty, the value returned
-     * by SERVER_NAME is used or 'localhost.localdomain'.
-     * @type string
+     * The hostname to use in the Message-ID header and as default HELO string.
+     * If empty, PHPMailer attempts to find one with, in order,
+     * $_SERVER['SERVER_NAME'], gethostname(), php_uname('n'), or the value
+     * 'localhost.localdomain'.
+     * @var string
      */
     public $Hostname = '';
 
     /**
-     * An ID to be used in the Message-Id header.
+     * An ID to be used in the Message-ID header.
      * If empty, a unique id will be generated.
-     * @type string
+     * You can set your own, but it must be in the format "<id@domain>",
+     * as defined in RFC5322 section 3.6.4 or it will be ignored.
+     * @see https://tools.ietf.org/html/rfc5322#section-3.6.4
+     * @var string
      */
     public $MessageID = '';
@@ -213 +212 @@
      * The message Date to be used in the Date header.
      * If empty, the current date will be added.
-     * @type string
+     * @var string
      */
     public $MessageDate = '';
@@ -223 +222 @@
      * for each host by using this format: [hostname:port]
      * (e.g. "smtp1.example.com:25;smtp2.example.com").
+     * You can also specify encryption type, for example:
+     * (e.g. "tls://smtp1.example.com:587;ssl://smtp2.example.com:465").
      * Hosts will be tried in order.
-     * @type string
+     * @var string
      */
     public $Host = 'localhost';
@@ -230 +231 @@
     /**
      * The default SMTP server port.
-     * @type int
-     * @Todo Why is this needed when the SMTP class takes care of it?
+     * @var integer
+     * @TODO Why is this needed when the SMTP class takes care of it?
      */
     public $Port = 25;
@@ -237 +238 @@
     /**
      * The SMTP HELO of the message.
-     * Default is $Hostname.
-     * @type string
+     * Default is $Hostname. If $Hostname is empty, PHPMailer attempts to find
+     * one with the same method described above for $Hostname.
+     * @var string
      * @see PHPMailer::$Hostname
      */
@@ -244 +246 @@
 
     /**
-     * The secure connection prefix.
-     * Options: "", "ssl" or "tls"
-     * @type string
+     * What kind of encryption to use on the SMTP connection.
+     * Options: '', 'ssl' or 'tls'
+     * @var string
      */
     public $SMTPSecure = '';
+
+    /**
+     * Whether to enable TLS encryption automatically if a server supports it,
+     * even if `SMTPSecure` is not set to 'tls'.
+     * Be aware that in PHP >= 5.6 this requires that the server's certificates are valid.
+     * @var boolean
+     */
+    public $SMTPAutoTLS = true;
 
     /**
      * Whether to use SMTP authentication.
      * Uses the Username and Password properties.
-     * @type bool
+     * @var boolean
      * @see PHPMailer::$Username
      * @see PHPMailer::$Password
@@ -260 +270 @@
 
     /**
+     * Options array passed to stream_context_create when connecting via SMTP.
+     * @var array
+     */
+    public $SMTPOptions = array();
+
+    /**
      * SMTP username.
-     * @type string
+     * @var string
      */
     public $Username = '';
@@ -267 +283 @@
     /**
      * SMTP password.
-     * @type string
+     * @var string
      */
     public $Password = '';
@@ -273 +289 @@
     /**
      * SMTP auth type.
-     * Options are LOGIN (default), PLAIN, NTLM, CRAM-MD5
-     * @type string
+     * Options are CRAM-MD5, LOGIN, PLAIN, attempted in that order if not specified
+     * @var string
      */
     public $AuthType = '';
@@ -281 +297 @@
      * SMTP realm.
      * Used for NTLM auth
-     * @type string
+     * @var string
      */
     public $Realm = '';
@@ -288 +304 @@
      * SMTP workstation.
      * Used for NTLM auth
-     * @type string
+     * @var string
      */
     public $Workstation = '';
@@ -294 +310 @@
     /**
      * The SMTP server timeout in seconds.
-     * @type int
-     */
-    public $Timeout = 10;
+     * Default of 5 minutes (300sec) is from RFC2821 section 4.5.3.2
+     * @var integer
+     */
+    public $Timeout = 300;
 
     /**
      * SMTP class debug output mode.
-     * Options: 0 = off, 1 = commands, 2 = commands and data
-     * @type int
+     * Debug output level.
+     * Options:
+     * * `0` No output
+     * * `1` Commands
+     * * `2` Data and commands
+     * * `3` As 2 plus connection status
+     * * `4` Low-level data output
+     * @var integer
      * @see SMTP::$do_debug
      */
@@ -307 +330 @@
 
     /**
-     * The function/method to use for debugging output.
-     * Options: "echo" or "error_log"
-     * @type string
+     * How to handle debug output.
+     * Options:
+     * * `echo` Output plain-text as-is, appropriate for CLI
+     * * `html` Output escaped, line breaks converted to `<br>`, appropriate for browser output
+     * * `error_log` Output to error log as configured in php.ini
+     *
+     * Alternatively, you can provide a callable expecting two params: a message string and the debug level:
+     * <code>
+     * $mail->Debugoutput = function($str, $level) {echo "debug level $level; message: $str";};
+     * </code>
+     * @var string|callable
      * @see SMTP::$Debugoutput
      */
-    public $Debugoutput = "echo";
+    public $Debugoutput = 'echo';
 
     /**
@@ -318 +349 @@
      * If this is set to true then to close the connection
      * requires an explicit call to smtpClose().
-     * @type bool
+     * @var boolean
      */
     public $SMTPKeepAlive = false;
@@ -325 +356 @@
      * Whether to split multiple to addresses into multiple messages
      * or send them all in one message.
-     * @type bool
+     * Only supported in `mail` and `sendmail` transports, not in SMTP.
+     * @var boolean
      */
     public $SingleTo = false;
@@ -331 +363 @@
     /**
      * Storage for addresses when SingleTo is enabled.
-     * @type array
-     * @todo This should really not be public
+     * @var array
+     * @TODO This should really not be public
      */
     public $SingleToArray = array();
@@ -339 +371 @@
      * Whether to generate VERP addresses on send.
      * Only applicable when sending via SMTP.
-     * @link http://en.wikipedia.org/wiki/Variable_envelope_return_path
-     * @type bool
+     * @link https://en.wikipedia.org/wiki/Variable_envelope_return_path
+     * @link http://www.postfix.org/VERP_README.html Postfix VERP info
+     * @var boolean
      */
     public $do_verp = false;
@@ -346 +379 @@
     /**
      * Whether to allow sending messages with an empty body.
-     * @type bool
+     * @var boolean
      */
     public $AllowEmpty = false;
@@ -354 +387 @@
      * @note The default remains "\n". We force CRLF where we know
      *        it must be used via self::CRLF.
-     * @type string
+     * @var string
      */
     public $LE = "\n";
@@ -360 +393 @@
     /**
      * DKIM selector.
-     * @type string
+     * @var string
      */
     public $DKIM_selector = '';
@@ -366 +399 @@
     /**
      * DKIM Identity.
-     * Usually the email address used as the source of the email
-     * @type string
+     * Usually the email address used as the source of the email.
+     * @var string
      */
     public $DKIM_identity = '';
@@ -374 +407 @@
      * DKIM passphrase.
      * Used if your key is encrypted.
-     * @type string
+     * @var string
      */
     public $DKIM_passphrase = '';
@@ -381 +414 @@
      * DKIM signing domain name.
      * @example 'example.com'
-     * @type string
+     * @var string
      */
     public $DKIM_domain = '';
@@ -387 +420 @@
     /**
      * DKIM private key file path.
-     * @type string
+     * @var string
      */
     public $DKIM_private = '';
+
+    /**
+     * DKIM private key string.
+     * If set, takes precedence over `$DKIM_private`.
+     * @var string
+     */
+    public $DKIM_private_string = '';
 
     /**
@@ -397 +437 @@
      * It is called out by send() for each email sent.
      *
-     * Value can be:
-     * - 'function_name' for function names
-     * - 'Class::Method' for static method calls
-     * - array($object, 'Method') for calling methods on $object
-     * See http://php.net/is_callable manual page for more details.
+     * Value can be any php callable: http://www.php.net/is_callable
      *
      * Parameters:
-     *   bool    $result        result of the send action
+     *   boolean $result        result of the send action
      *   string  $to            email address of the recipient
      *   string  $cc            cc email addresses
@@ -411 +447 @@
      *   string  $body          the email body
      *   string  $from          email address of sender
-     * 
-     * @type string
+     * @var string
      */
     public $action_function = '';
 
     /**
-     * What to use in the X-Mailer header.
-     * Options: null for default, whitespace for none, or a string to use
-     * @type string
+     * What to put in the X-Mailer header.
+     * Options: An empty string for PHPMailer default, whitespace for none, or a string to use
+     * @var string
      */
     public $XMailer = '';
 
     /**
+     * Which validator to use by default when validating email addresses.
+     * May be a callable to inject your own validator, but there are several built-in validators.
+     * @see PHPMailer::validateAddress()
+     * @var string|callable
+     * @static
+     */
+    public static $validator = 'auto';
+
+    /**
      * An instance of the SMTP sender class.
-     * @type SMTP
+     * @var SMTP
      * @access protected
      */
@@ -431 +475 @@
 
     /**
-     * The array of 'to' addresses.
-     * @type array
+     * The array of 'to' names and addresses.
+     * @var array
      * @access protected
      */
@@ -438 +482 @@
 
     /**
-     * The array of 'cc' addresses.
-     * @type array
+     * The array of 'cc' names and addresses.
+     * @var array
      * @access protected
      */
@@ -445 +489 @@
 
     /**
-     * The array of 'bcc' addresses.
-     * @type array
+     * The array of 'bcc' names and addresses.
+     * @var array
      * @access protected
      */
@@ -453 +497 @@
     /**
      * The array of reply-to names and addresses.
-     * @type array
+     * @var array
      * @access protected
      */
@@ -460 +504 @@
     /**
      * An array of all kinds of addresses.
-     * Includes all of $to, $cc, $bcc, $replyto
-     * @type array
+     * Includes all of $to, $cc, $bcc
+     * @var array
      * @access protected
+     * @see PHPMailer::$to @see PHPMailer::$cc @see PHPMailer::$bcc
      */
     protected $all_recipients = array();
 
     /**
+     * An array of names and addresses queued for validation.
+     * In send(), valid and non duplicate entries are moved to $all_recipients
+     * and one of $to, $cc, or $bcc.
+     * This array is used only for addresses with IDN.
+     * @var array
+     * @access protected
+     * @see PHPMailer::$to @see PHPMailer::$cc @see PHPMailer::$bcc
+     * @see PHPMailer::$all_recipients
+     */
+    protected $RecipientsQueue = array();
+
+    /**
+     * An array of reply-to names and addresses queued for validation.
+     * In send(), valid and non duplicate entries are moved to $ReplyTo.
+     * This array is used only for addresses with IDN.
+     * @var array
+     * @access protected
+     * @see PHPMailer::$ReplyTo
+     */
+    protected $ReplyToQueue = array();
+
+    /**
      * The array of attachments.
-     * @type array
+     * @var array
      * @access protected
      */
@@ -475 +542 @@
     /**
      * The array of custom headers.
-     * @type array
+     * @var array
      * @access protected
      */
@@ -482 +549 @@
     /**
      * The most recent Message-ID (including angular brackets).
-     * @type string
+     * @var string
      * @access protected
      */
@@ -489 +556 @@
     /**
      * The message's MIME type.
-     * @type string
+     * @var string
      * @access protected
      */
@@ -496 +563 @@
     /**
      * The array of MIME boundary strings.
-     * @type array
+     * @var array
      * @access protected
      */
@@ -503 +570 @@
     /**
      * The array of available languages.
-     * @type array
+     * @var array
      * @access protected
      */
@@ -510 +577 @@
     /**
      * The number of errors encountered.
-     * @type integer
+     * @var integer
      * @access protected
      */
@@ -517 +584 @@
     /**
      * The S/MIME certificate file path.
-     * @type string
+     * @var string
      * @access protected
      */
@@ -524 +591 @@
     /**
      * The S/MIME key file path.
-     * @type string
+     * @var string
      * @access protected
      */
     protected $sign_key_file = '';
+
+    /**
+     * The optional S/MIME extra certificates ("CA Chain") file path.
+     * @var string
+     * @access protected
+     */
+    protected $sign_extracerts_file = '';
 
     /**
      * The S/MIME password for the key.
      * Used only if the key is encrypted.
-     * @type string
+     * @var string
      * @access protected
      */
@@ -539 +613 @@
     /**
      * Whether to throw exceptions for errors.
-     * @type bool
+     * @var boolean
      * @access protected
      */
@@ -545 +619 @@
 
     /**
-     * Error severity: message only, continue processing
+     * Unique ID used for message ID and boundaries.
+     * @var string
+     * @access protected
+     */
+    protected $uniqueid = '';
+
+    /**
+     * Error severity: message only, continue processing.
      */
     const STOP_MESSAGE = 0;
 
     /**
-     * Error severity: message, likely ok to continue processing
+     * Error severity: message, likely ok to continue processing.
      */
     const STOP_CONTINUE = 1;
 
     /**
-     * Error severity: message, plus full stop, critical error reached
+     * Error severity: message, plus full stop, critical error reached.
      */
     const STOP_CRITICAL = 2;
 
     /**
-     * SMTP RFC standard line ending
+     * SMTP RFC standard line ending.
      */
     const CRLF = "\r\n";
 
     /**
-     * Constructor
-     * @param bool $exceptions Should we throw external exceptions?
-     */
-    public function __construct($exceptions = false)
-    {
-        $this->exceptions = ($exceptions == true);
+     * The maximum line length allowed by RFC 2822 section 2.1.1
+     * @var integer
+     */
+    const MAX_LINE_LENGTH = 998;
+
+    /**
+     * Constructor.
+     * @param boolean $exceptions Should we throw external exceptions?
+     */
+    public function __construct($exceptions = null)
+    {
+        if ($exceptions !== null) {
+            $this->exceptions = (boolean)$exceptions;
+        }
     }
 
@@ -578 +667 @@
     public function __destruct()
     {
-        if ($this->Mailer == 'smtp') { //close any open SMTP connection nicely
-            $this->smtpClose();
-        }
+        //Close any open SMTP connection nicely
+        $this->smtpClose();
     }
 
@@ -594 +682 @@
      * @param string $params Params
      * @access private
-     * @return bool
+     * @return boolean
      */
     private function mailPassthru($to, $subject, $body, $header, $params)
     {
-        if (ini_get('safe_mode') || !($this->UseSendmailOptions)) {
-            $rt = @mail($to, $this->encodeHeader($this->secureHeader($subject)), $body, $header);
+        //Check overloading of mail function to avoid double-encoding
+        if (ini_get('mbstring.func_overload') & 1) {
+            $subject = $this->secureHeader($subject);
         } else {
-            $rt = @mail($to, $this->encodeHeader($this->secureHeader($subject)), $body, $header, $params);
-        }
-        return $rt;
-    }
-
+            $subject = $this->encodeHeader($this->secureHeader($subject));
+        }
+
+        //Can't use additional_parameters in safe_mode, calling mail() with null params breaks
+        //@link http://php.net/manual/en/function.mail.php
+        if (ini_get('safe_mode') or !$this->UseSendmailOptions or is_null($params)) {
+            $result = @mail($to, $subject, $body, $header);
+        } else {
+            $result = @mail($to, $subject, $body, $header, $params);
+        }
+        return $result;
+    }
     /**
      * Output debugging info via user-defined method.
-     * Only if debug output is enabled.
+     * Only generates output if SMTP debug output is enabled (@see SMTP::$do_debug).
      * @see PHPMailer::$Debugoutput
      * @see PHPMailer::$SMTPDebug
@@ -615 +711 @@
     protected function edebug($str)
     {
-        if (!$this->SMTPDebug) {
+        if ($this->SMTPDebug <= 0) {
+            return;
+        }
+        //Avoid clash with built-in function names
+        if (!in_array($this->Debugoutput, array('error_log', 'html', 'echo')) and is_callable($this->Debugoutput)) {
+            call_user_func($this->Debugoutput, $str, $this->SMTPDebug);
             return;
         }
         switch ($this->Debugoutput) {
             case 'error_log':
+                //Don't output, just log
                 error_log($str);
                 break;
             case 'html':
-                //Cleans up output a bit for a better looking display that's HTML-safe
-                echo htmlentities(preg_replace('/[\r\n]+/', '', $str), ENT_QUOTES, $this->CharSet) . "<br>\n";
+                //Cleans up output a bit for a better looking, HTML-safe output
+                echo htmlentities(
+                    preg_replace('/[\r\n]+/', '', $str),
+                    ENT_QUOTES,
+                    'UTF-8'
+                )
+                . "<br>\n";
                 break;
             case 'echo':
             default:
-                //Just echoes exactly what was received
-                echo $str;
+                //Normalize line breaks
+                $str = preg_replace('/\r\n?/ms', "\n", $str);
+                echo gmdate('Y-m-d H:i:s') . "\t" . str_replace(
+                    "\n",
+                    "\n                   \t                  ",
+                    trim($str)
+                ) . "\n";
         }
     }
@@ -635 +747 @@
     /**
      * Sets message type to HTML or plain.
-     * @param bool $ishtml True for HTML mode.
+     * @param boolean $isHtml True for HTML mode.
      * @return void
      */
-    public function isHTML($ishtml = true)
-    {
-        if ($ishtml) {
+    public function isHTML($isHtml = true)
+    {
+        if ($isHtml) {
             $this->ContentType = 'text/html';
         } else {
@@ -671 +783 @@
     public function isSendmail()
     {
-        if (!stristr(ini_get('sendmail_path'), 'sendmail')) {
-            $this->Sendmail = '/var/qmail/bin/sendmail';
+        $ini_sendmail_path = ini_get('sendmail_path');
+
+        if (!stristr($ini_sendmail_path, 'sendmail')) {
+            $this->Sendmail = '/usr/sbin/sendmail';
+        } else {
+            $this->Sendmail = $ini_sendmail_path;
         }
         $this->Mailer = 'sendmail';
@@ -683 +799 @@
     public function isQmail()
     {
-        if (stristr(ini_get('sendmail_path'), 'qmail')) {
-            $this->Sendmail = '/var/qmail/bin/sendmail';
-        }
-        $this->Mailer = 'sendmail';
+        $ini_sendmail_path = ini_get('sendmail_path');
+
+        if (!stristr($ini_sendmail_path, 'qmail')) {
+            $this->Sendmail = '/var/qmail/bin/qmail-inject';
+        } else {
+            $this->Sendmail = $ini_sendmail_path;
+        }
+        $this->Mailer = 'qmail';
     }
 
     /**
      * Add a "To" address.
-     * @param string $address
+     * @param string $address The email address to send to
      * @param string $name
-     * @return bool true on success, false if address already used
+     * @return boolean true on success, false if address already used or invalid in some way
      */
     public function addAddress($address, $name = '')
     {
-        return $this->addAnAddress('to', $address, $name);
+        return $this->addOrEnqueueAnAddress('to', $address, $name);
     }
 
@@ -703 +823 @@
      * Add a "CC" address.
      * @note: This function works with the SMTP mailer on win32, not with the "mail" mailer.
-     * @param string $address
+     * @param string $address The email address to send to
      * @param string $name
-     * @return bool true on success, false if address already used
+     * @return boolean true on success, false if address already used or invalid in some way
      */
     public function addCC($address, $name = '')
     {
-        return $this->addAnAddress('cc', $address, $name);
+        return $this->addOrEnqueueAnAddress('cc', $address, $name);
     }
 
@@ -715 +835 @@
      * Add a "BCC" address.
      * @note: This function works with the SMTP mailer on win32, not with the "mail" mailer.
-     * @param string $address
-     * @param string $name
-     * @return bool true on success, false if address already used
-     */
-    public function addBCC($address, $name = '')
-    {
-        return $this->addAnAddress('bcc', $address, $name);
-    }
-
-    /**
-     * Add a "Reply-to" address.
-     * @param string $address
-     * @param string $name
-     * @return bool
-     */
-    public function addReplyTo($address, $name = '')
-    {
-        return $this->addAnAddress('Reply-To', $address, $name);
-    }
-
-    /**
-     * Add an address to one of the recipient arrays.
-     * Addresses that have been added already return false, but do not throw exceptions
-     * @param string $kind One of 'to', 'cc', 'bcc', 'ReplyTo'
      * @param string $address The email address to send to
      * @param string $name
+     * @return boolean true on success, false if address already used or invalid in some way
+     */
+    public function addBCC($address, $name = '')
+    {
+        return $this->addOrEnqueueAnAddress('bcc', $address, $name);
+    }
+
+    /**
+     * Add a "Reply-To" address.
+     * @param string $address The email address to reply to
+     * @param string $name
+     * @return boolean true on success, false if address already used or invalid in some way
+     */
+    public function addReplyTo($address, $name = '')
+    {
+        return $this->addOrEnqueueAnAddress('Reply-To', $address, $name);
+    }
+
+    /**
+     * Add an address to one of the recipient arrays or to the ReplyTo array. Because PHPMailer
+     * can't validate addresses with an IDN without knowing the PHPMailer::$CharSet (that can still
+     * be modified after calling this function), addition of such addresses is delayed until send().
+     * Addresses that have been added already return false, but do not throw exceptions.
+     * @param string $kind One of 'to', 'cc', 'bcc', or 'ReplyTo'
+     * @param string $address The email address to send, resp. to reply to
+     * @param string $name
      * @throws phpmailerException
-     * @return bool true on success, false if address already used or invalid in some way
+     * @return boolean true on success, false if address already used or invalid in some way
      * @access protected
      */
-    protected function addAnAddress($kind, $address, $name = '')
-    {
-        if (!preg_match('/^(to|cc|bcc|Reply-To)$/', $kind)) {
-            $this->setError($this->lang('Invalid recipient array') . ': ' . $kind);
-            if ($this->exceptions) {
-                throw new phpmailerException('Invalid recipient array: ' . $kind);
-            }
-            $this->edebug($this->lang('Invalid recipient array') . ': ' . $kind);
-            return false;
-        }
+    protected function addOrEnqueueAnAddress($kind, $address, $name)
+    {
         $address = trim($address);
         $name = trim(preg_replace('/[\r\n]+/', '', $name)); //Strip breaks and trim
+        if (($pos = strrpos($address, '@')) === false) {
+            // At-sign is misssing.
+            $error_message = $this->lang('invalid_address') . " (addAnAddress $kind): $address";
+            $this->setError($error_message);
+            $this->edebug($error_message);
+            if ($this->exceptions) {
+                throw new phpmailerException($error_message);
+            }
+            return false;
+        }
+        $params = array($kind, $address, $name);
+        // Enqueue addresses with IDN until we know the PHPMailer::$CharSet.
+        if ($this->has8bitChars(substr($address, ++$pos)) and $this->idnSupported()) {
+            if ($kind != 'Reply-To') {
+                if (!array_key_exists($address, $this->RecipientsQueue)) {
+                    $this->RecipientsQueue[$address] = $params;
+                    return true;
+                }
+            } else {
+                if (!array_key_exists($address, $this->ReplyToQueue)) {
+                    $this->ReplyToQueue[$address] = $params;
+                    return true;
+                }
+            }
+            return false;
+        }
+        // Immediately add standard addresses without IDN.
+        return call_user_func_array(array($this, 'addAnAddress'), $params);
+    }
+
+    /**
+     * Add an address to one of the recipient arrays or to the ReplyTo array.
+     * Addresses that have been added already return false, but do not throw exceptions.
+     * @param string $kind One of 'to', 'cc', 'bcc', or 'ReplyTo'
+     * @param string $address The email address to send, resp. to reply to
+     * @param string $name
+     * @throws phpmailerException
+     * @return boolean true on success, false if address already used or invalid in some way
+     * @access protected
+     */
+    protected function addAnAddress($kind, $address, $name = '')
+    {
+        if (!in_array($kind, array('to', 'cc', 'bcc', 'Reply-To'))) {
+            $error_message = $this->lang('Invalid recipient kind: ') . $kind;
+            $this->setError($error_message);
+            $this->edebug($error_message);
+            if ($this->exceptions) {
+                throw new phpmailerException($error_message);
+            }
+            return false;
+        }
         if (!$this->validateAddress($address)) {
-            $this->setError($this->lang('invalid_address') . ': ' . $address);
+            $error_message = $this->lang('invalid_address') . " (addAnAddress $kind): $address";
+            $this->setError($error_message);
+            $this->edebug($error_message);
             if ($this->exceptions) {
-                throw new phpmailerException($this->lang('invalid_address') . ': ' . $address);
-            }
-            $this->edebug($this->lang('invalid_address') . ': ' . $address);
+                throw new phpmailerException($error_message);
+            }
             return false;
         }
         if ($kind != 'Reply-To') {
-            if (!isset($this->all_recipients[strtolower($address)])) {
+            if (!array_key_exists(strtolower($address), $this->all_recipients)) {
                 array_push($this->$kind, array($address, $name));
                 $this->all_recipients[strtolower($address)] = true;
@@ -781 +947 @@
 
     /**
+     * Parse and validate a string containing one or more RFC822-style comma-separated email addresses
+     * of the form "display name <address>" into an array of name/address pairs.
+     * Uses the imap_rfc822_parse_adrlist function if the IMAP extension is available.
+     * Note that quotes in the name part are removed.
+     * @param string $addrstr The address list string
+     * @param bool $useimap Whether to use the IMAP extension to parse the list
+     * @return array
+     * @link http://www.andrew.cmu.edu/user/agreen1/testing/mrbs/web/Mail/RFC822.php A more careful implementation
+     */
+    public function parseAddresses($addrstr, $useimap = true)
+    {
+        $addresses = array();
+        if ($useimap and function_exists('imap_rfc822_parse_adrlist')) {
+            //Use this built-in parser if it's available
+            $list = imap_rfc822_parse_adrlist($addrstr, '');
+            foreach ($list as $address) {
+                if ($address->host != '.SYNTAX-ERROR.') {
+                    if ($this->validateAddress($address->mailbox . '@' . $address->host)) {
+                        $addresses[] = array(
+                            'name' => (property_exists($address, 'personal') ? $address->personal : ''),
+                            'address' => $address->mailbox . '@' . $address->host
+                        );
+                    }
+                }
+            }
+        } else {
+            //Use this simpler parser
+            $list = explode(',', $addrstr);
+            foreach ($list as $address) {
+                $address = trim($address);
+                //Is there a separate name part?
+                if (strpos($address, '<') === false) {
+                    //No separate name, just use the whole thing
+                    if ($this->validateAddress($address)) {
+                        $addresses[] = array(
+                            'name' => '',
+                            'address' => $address
+                        );
+                    }
+                } else {
+                    list($name, $email) = explode('<', $address);
+                    $email = trim(str_replace('>', '', $email));
+                    if ($this->validateAddress($email)) {
+                        $addresses[] = array(
+                            'name' => trim(str_replace(array('"', "'"), '', $name)),
+                            'address' => $email
+                        );
+                    }
+                }
+            }
+        }
+        return $addresses;
+    }
+
+    /**
      * Set the From and FromName properties.
      * @param string $address
      * @param string $name
-     * @param bool $auto Whether to also set the Sender address, defaults to true
+     * @param boolean $auto Whether to also set the Sender address, defaults to true
      * @throws phpmailerException
-     * @return bool
+     * @return boolean
      */
     public function setFrom($address, $name = '', $auto = true)
@@ -792 +1013 @@
         $address = trim($address);
         $name = trim(preg_replace('/[\r\n]+/', '', $name)); //Strip breaks and trim
-        if (!$this->validateAddress($address)) {
-            $this->setError($this->lang('invalid_address') . ': ' . $address);
+        // Don't validate now addresses with IDN. Will be done in send().
+        if (($pos = strrpos($address, '@')) === false or
+            (!$this->has8bitChars(substr($address, ++$pos)) or !$this->idnSupported()) and
+            !$this->validateAddress($address)) {
+            $error_message = $this->lang('invalid_address') . " (setFrom) $address";
+            $this->setError($error_message);
+            $this->edebug($error_message);
             if ($this->exceptions) {
-                throw new phpmailerException($this->lang('invalid_address') . ': ' . $address);
-            }
-            $this->edebug($this->lang('invalid_address') . ': ' . $address);
+                throw new phpmailerException($error_message);
+            }
             return false;
         }
@@ -825 +1050 @@
      * Check that a string looks like an email address.
      * @param string $address The email address to check
-     * @param string $patternselect A selector for the validation pattern to use :
-     *   'auto' - pick best one automatically;
-     *   'pcre8' - use the squiloople.com pattern, requires PCRE > 8.0, PHP >= 5.3.2, 5.2.14;
-     *   'pcre' - use old PCRE implementation;
-     *   'php' - use PHP built-in FILTER_VALIDATE_EMAIL; faster, less thorough;
-     *   'noregex' - super fast, really dumb.
-     * @return bool
+     * @param string|callable $patternselect A selector for the validation pattern to use :
+     * * `auto` Pick best pattern automatically;
+     * * `pcre8` Use the squiloople.com pattern, requires PCRE > 8.0, PHP >= 5.3.2, 5.2.14;
+     * * `pcre` Use old PCRE implementation;
+     * * `php` Use PHP built-in FILTER_VALIDATE_EMAIL;
+     * * `html5` Use the pattern given by the HTML5 spec for 'email' type form input elements.
+     * * `noregex` Don't use a regex: super fast, really dumb.
+     * Alternatively you may pass in a callable to inject your own validator, for example:
+     * PHPMailer::validateAddress('user@example.com', function($address) {
+     *     return (strpos($address, '@') !== false);
+     * });
+     * You can also set the PHPMailer::$validator static to a callable, allowing built-in methods to use your validator.
+     * @return boolean
      * @static
      * @access public
      */
-    public static function validateAddress($address, $patternselect = 'auto')
-    {
-        if ($patternselect == 'auto') {
-            if (defined(
-                'PCRE_VERSION'
-            )
-            ) { //Check this instead of extension_loaded so it works when that function is disabled
-                if (version_compare(PCRE_VERSION, '8.0') >= 0) {
+    public static function validateAddress($address, $patternselect = null)
+    {
+        if (is_null($patternselect)) {
+            $patternselect = self::$validator;
+        }
+        if (is_callable($patternselect)) {
+            return call_user_func($patternselect, $address);
+        }
+        //Reject line breaks in addresses; it's valid RFC5322, but not RFC5321
+        if (strpos($address, "\n") !== false or strpos($address, "\r") !== false) {
+            return false;
+        }
+        if (!$patternselect or $patternselect == 'auto') {
+            //Check this constant first so it works when extension_loaded() is disabled by safe mode
+            //Constant was added in PHP 5.2.4
+            if (defined('PCRE_VERSION')) {
+                //This pattern can get stuck in a recursive loop in PCRE <= 8.0.2
+                if (version_compare(PCRE_VERSION, '8.0.3') >= 0) {
                     $patternselect = 'pcre8';
                 } else {
                     $patternselect = 'pcre';
                 }
+            } elseif (function_exists('extension_loaded') and extension_loaded('pcre')) {
+                //Fall back to older PCRE
+                $patternselect = 'pcre';
             } else {
                 //Filter_var appeared in PHP 5.2.0 and does not require the PCRE extension
@@ -859 +1103 @@
             case 'pcre8':
                 /**
-                 * Conforms to RFC5322: Uses *correct* regex on which FILTER_VALIDATE_EMAIL is
-                 * based; So why not use FILTER_VALIDATE_EMAIL? Because it was broken to
-                 * not allow a@b type valid addresses :(
+                 * Uses the same RFC5322 regex on which FILTER_VALIDATE_EMAIL is based, but allows dotless domains.
                  * @link http://squiloople.com/2009/12/20/email-address-validation/
                  * @copyright 2009-2010 Michael Rushton
                  * Feel free to use and redistribute this code. But please keep this copyright notice.
                  */
-                return (bool)preg_match(
+                return (boolean)preg_match(
                     '/^(?!(?>(?1)"?(?>\\\[ -~]|[^"])"?(?1)){255,})(?!(?>(?1)"?(?>\\\[ -~]|[^"])"?(?1)){65,}@)' .
                     '((?>(?>(?>((?>(?>(?>\x0D\x0A)?[\t ])+|(?>[\t ]*\x0D\x0A)?[\t ]+)?)(\((?>(?2)' .
@@ -878 +1120 @@
                     $address
                 );
-                break;
             case 'pcre':
                 //An older regex that doesn't need a recent PCRE
-                return (bool)preg_match(
+                return (boolean)preg_match(
                     '/^(?!(?>"?(?>\\\[ -~]|[^"])"?){255,})(?!(?>"?(?>\\\[ -~]|[^"])"?){65,}@)(?>' .
                     '[!#-\'*+\/-9=?^-~-]+|"(?>(?>[\x01-\x08\x0B\x0C\x0E-!#-\[\]-\x7F]|\\\[\x00-\xFF]))*")' .
@@ -894 +1135 @@
                     $address
                 );
-                break;
-            case 'php':
-            default:
-                return (bool)filter_var($address, FILTER_VALIDATE_EMAIL);
-                break;
+            case 'html5':
+                /**
+                 * This is the pattern used in the HTML5 spec for validation of 'email' type form input elements.
+                 * @link http://www.whatwg.org/specs/web-apps/current-work/#e-mail-state-(type=email)
+                 */
+                return (boolean)preg_match(
+                    '/^[a-zA-Z0-9.!#$%&\'*+\/=?^_`{|}~-]+@[a-zA-Z0-9](?:[a-zA-Z0-9-]{0,61}' .
+                    '[a-zA-Z0-9])?(?:\.[a-zA-Z0-9](?:[a-zA-Z0-9-]{0,61}[a-zA-Z0-9])?)*$/sD',
+                    $address
+                );
             case 'noregex':
                 //No PCRE! Do something _very_ approximate!
@@ -905 +1151 @@
                     and strpos($address, '@') >= 1
                     and strpos($address, '@') != strlen($address) - 1);
-                break;
-        }
+            case 'php':
+            default:
+                return (boolean)filter_var($address, FILTER_VALIDATE_EMAIL);
+        }
+    }
+
+    /**
+     * Tells whether IDNs (Internationalized Domain Names) are supported or not. This requires the
+     * "intl" and "mbstring" PHP extensions.
+     * @return bool "true" if required functions for IDN support are present
+     */
+    public function idnSupported()
+    {
+        // @TODO: Write our own "idn_to_ascii" function for PHP <= 5.2.
+        return function_exists('idn_to_ascii') and function_exists('mb_convert_encoding');
+    }
+
+    /**
+     * Converts IDN in given email address to its ASCII form, also known as punycode, if possible.
+     * Important: Address must be passed in same encoding as currently set in PHPMailer::$CharSet.
+     * This function silently returns unmodified address if:
+     * - No conversion is necessary (i.e. domain name is not an IDN, or is already in ASCII form)
+     * - Conversion to punycode is impossible (e.g. required PHP functions are not available)
+     *   or fails for any reason (e.g. domain has characters not allowed in an IDN)
+     * @see PHPMailer::$CharSet
+     * @param string $address The email address to convert
+     * @return string The encoded address in ASCII form
+     */
+    public function punyencodeAddress($address)
+    {
+        // Verify we have required functions, CharSet, and at-sign.
+        if ($this->idnSupported() and
+            !empty($this->CharSet) and
+            ($pos = strrpos($address, '@')) !== false) {
+            $domain = substr($address, ++$pos);
+            // Verify CharSet string is a valid one, and domain properly encoded in this CharSet.
+            if ($this->has8bitChars($domain) and @mb_check_encoding($domain, $this->CharSet)) {
+                $domain = mb_convert_encoding($domain, 'UTF-8', $this->CharSet);
+                if (($punycode = defined('INTL_IDNA_VARIANT_UTS46') ?
+                    idn_to_ascii($domain, 0, INTL_IDNA_VARIANT_UTS46) :
+                    idn_to_ascii($domain)) !== false) {
+                    return substr($address, 0, $pos) . $punycode;
+                }
+            }
+        }
+        return $address;
     }
 
@@ -912 +1202 @@
      * Create a message and send it.
      * Uses the sending method specified by $Mailer.
-     * Returns false on error - Use the ErrorInfo variable to view description of the error.
      * @throws phpmailerException
-     * @return bool
+     * @return boolean false on error - See the ErrorInfo property for details of the error.
      */
     public function send()
@@ -923 +1212 @@
             }
             return $this->postSend();
-        } catch (phpmailerException $e) {
+        } catch (phpmailerException $exc) {
             $this->mailHeader = '';
-            $this->setError($e->getMessage());
+            $this->setError($exc->getMessage());
             if ($this->exceptions) {
-                throw $e;
+                throw $exc;
             }
             return false;
@@ -936 +1225 @@
      * Prepare a message for sending.
      * @throws phpmailerException
-     * @return bool
+     * @return boolean
      */
     public function preSend()
     {
         try {
-            $this->mailHeader = "";
+            $this->error_count = 0; // Reset errors
+            $this->mailHeader = '';
+
+            // Dequeue recipient and Reply-To addresses with IDN
+            foreach (array_merge($this->RecipientsQueue, $this->ReplyToQueue) as $params) {
+                $params[1] = $this->punyencodeAddress($params[1]);
+                call_user_func_array(array($this, 'addAnAddress'), $params);
+            }
             if ((count($this->to) + count($this->cc) + count($this->bcc)) < 1) {
                 throw new phpmailerException($this->lang('provide_address'), self::STOP_CRITICAL);
             }
 
+            // Validate From, Sender, and ConfirmReadingTo addresses
+            foreach (array('From', 'Sender', 'ConfirmReadingTo') as $address_kind) {
+                $this->$address_kind = trim($this->$address_kind);
+                if (empty($this->$address_kind)) {
+                    continue;
+                }
+                $this->$address_kind = $this->punyencodeAddress($this->$address_kind);
+                if (!$this->validateAddress($this->$address_kind)) {
+                    $error_message = $this->lang('invalid_address') . ' (punyEncode) ' . $this->$address_kind;
+                    $this->setError($error_message);
+                    $this->edebug($error_message);
+                    if ($this->exceptions) {
+                        throw new phpmailerException($error_message);
+                    }
+                    return false;
+                }
+            }
+
             // Set whether the message is multipart/alternative
-            if (!empty($this->AltBody)) {
+            if ($this->alternativeExists()) {
                 $this->ContentType = 'multipart/alternative';
             }
 
-            $this->error_count = 0; // reset errors
             $this->setMessageType();
             // Refuse to send an empty message unless we are specifically allowing it
@@ -958 +1271 @@
             }
 
+            // Create body before headers in case body makes changes to headers (e.g. altering transfer encoding)
+            $this->MIMEHeader = '';
+            $this->MIMEBody = $this->createBody();
+            // createBody may have added some headers, so retain them
+            $tempheaders = $this->MIMEHeader;
             $this->MIMEHeader = $this->createHeader();
-            $this->MIMEBody = $this->createBody();
+            $this->MIMEHeader .= $tempheaders;
 
             // To capture the complete message when using mail(), create
@@ -965 +1283 @@
             if ($this->Mailer == 'mail') {
                 if (count($this->to) > 0) {
-                    $this->mailHeader .= $this->addrAppend("To", $this->to);
+                    $this->mailHeader .= $this->addrAppend('To', $this->to);
                 } else {
-                    $this->mailHeader .= $this->headerLine("To", "undisclosed-recipients:;");
+                    $this->mailHeader .= $this->headerLine('To', 'undisclosed-recipients:;');
                 }
                 $this->mailHeader .= $this->headerLine(
@@ -977 +1295 @@
             // Sign with DKIM if enabled
             if (!empty($this->DKIM_domain)
-                && !empty($this->DKIM_private)
                 && !empty($this->DKIM_selector)
-                && !empty($this->DKIM_domain)
-                && file_exists($this->DKIM_private)) {
+                && (!empty($this->DKIM_private_string)
+                   || (!empty($this->DKIM_private) && file_exists($this->DKIM_private))
+                )
+            ) {
                 $header_dkim = $this->DKIM_Add(
                     $this->MIMEHeader . $this->mailHeader,
@@ -990 +1309 @@
             }
             return true;
-
-        } catch (phpmailerException $e) {
-            $this->setError($e->getMessage());
+        } catch (phpmailerException $exc) {
+            $this->setError($exc->getMessage());
             if ($this->exceptions) {
-                throw $e;
+                throw $exc;
             }
             return false;
@@ -1004 +1322 @@
      * Send the email via the selected mechanism
      * @throws phpmailerException
-     * @return bool
+     * @return boolean
      */
     public function postSend()
@@ -1012 +1330 @@
             switch ($this->Mailer) {
                 case 'sendmail':
+                case 'qmail':
                     return $this->sendmailSend($this->MIMEHeader, $this->MIMEBody);
                 case 'smtp':
@@ -1018 +1337 @@
                     return $this->mailSend($this->MIMEHeader, $this->MIMEBody);
                 default:
+                    $sendMethod = $this->Mailer.'Send';
+                    if (method_exists($this, $sendMethod)) {
+                        return $this->$sendMethod($this->MIMEHeader, $this->MIMEBody);
+                    }
+
                     return $this->mailSend($this->MIMEHeader, $this->MIMEBody);
             }
-        } catch (phpmailerException $e) {
-            $this->setError($e->getMessage());
+        } catch (phpmailerException $exc) {
+            $this->setError($exc->getMessage());
+            $this->edebug($exc->getMessage());
             if ($this->exceptions) {
-                throw $e;
-            }
-            $this->edebug($e->getMessage() . "\n");
+                throw $exc;
+            }
         }
         return false;
@@ -1037 +1361 @@
      * @throws phpmailerException
      * @access protected
-     * @return bool
+     * @return boolean
      */
     protected function sendmailSend($header, $body)
     {
-        if ($this->Sender != '') {
-            $sendmail = sprintf("%s -oi -f%s -t", escapeshellcmd($this->Sendmail), escapeshellarg($this->Sender));
+        // CVE-2016-10033, CVE-2016-10045: Don't pass -f if characters will be escaped.
+        if (!empty($this->Sender) and self::isShellSafe($this->Sender)) {
+            if ($this->Mailer == 'qmail') {
+                $sendmailFmt = '%s -f%s';
+            } else {
+                $sendmailFmt = '%s -oi -f%s -t';
+            }
         } else {
-            $sendmail = sprintf("%s -oi -t", escapeshellcmd($this->Sendmail));
-        }
-        if ($this->SingleTo === true) {
-            foreach ($this->SingleToArray as $val) {
+            if ($this->Mailer == 'qmail') {
+                $sendmailFmt = '%s';
+            } else {
+                $sendmailFmt = '%s -oi -t';
+            }
+        }
+
+        // TODO: If possible, this should be changed to escapeshellarg.  Needs thorough testing.
+        $sendmail = sprintf($sendmailFmt, escapeshellcmd($this->Sendmail), $this->Sender);
+
+        if ($this->SingleTo) {
+            foreach ($this->SingleToArray as $toAddr) {
                 if (!@$mail = popen($sendmail, 'w')) {
                     throw new phpmailerException($this->lang('execute') . $this->Sendmail, self::STOP_CRITICAL);
                 }
-                fputs($mail, "To: " . $val . "\n");
+                fputs($mail, 'To: ' . $toAddr . "\n");
                 fputs($mail, $header);
                 fputs($mail, $body);
                 $result = pclose($mail);
-                // implement call back function if it exists
-                $isSent = ($result == 0) ? 1 : 0;
-                $this->doCallback($isSent, $val, $this->cc, $this->bcc, $this->Subject, $body, $this->From);
+                $this->doCallback(
+                    ($result == 0),
+                    array($toAddr),
+                    $this->cc,
+                    $this->bcc,
+                    $this->Subject,
+                    $body,
+                    $this->From
+                );
                 if ($result != 0) {
                     throw new phpmailerException($this->lang('execute') . $this->Sendmail, self::STOP_CRITICAL);
@@ -1069 +1412 @@
             fputs($mail, $body);
             $result = pclose($mail);
-            // implement call back function if it exists
-            $isSent = ($result == 0) ? 1 : 0;
-            $this->doCallback($isSent, $this->to, $this->cc, $this->bcc, $this->Subject, $body, $this->From);
+            $this->doCallback(
+                ($result == 0),
+                $this->to,
+                $this->cc,
+                $this->bcc,
+                $this->Subject,
+                $body,
+                $this->From
+            );
             if ($result != 0) {
                 throw new phpmailerException($this->lang('execute') . $this->Sendmail, self::STOP_CRITICAL);
             }
         }
+        return true;
+    }
+
+    /**
+     * Fix CVE-2016-10033 and CVE-2016-10045 by disallowing potentially unsafe shell characters.
+     *
+     * Note that escapeshellarg and escapeshellcmd are inadequate for our purposes, especially on Windows.
+     * @param string $string The string to be validated
+     * @see https://github.com/PHPMailer/PHPMailer/issues/924 CVE-2016-10045 bug report
+     * @access protected
+     * @return boolean
+     */
+    protected static function isShellSafe($string)
+    {
+        // Future-proof
+        if (escapeshellcmd($string) !== $string
+            or !in_array(escapeshellarg($string), array("'$string'", "\"$string\""))
+        ) {
+            return false;
+        }
+
+        $length = strlen($string);
+
+        for ($i = 0; $i < $length; $i++) {
+            $c = $string[$i];
+
+            // All other characters have a special meaning in at least one common shell, including = and +.
+            // Full stop (.) has a special meaning in cmd.exe, but its impact should be negligible here.
+            // Note that this does permit non-Latin alphanumeric characters based on the current locale.
+            if (!ctype_alnum($c) && strpos('@_-.', $c) === false) {
+                return false;
+            }
+        }
+
         return true;
     }
@@ -1086 +1469 @@
      * @throws phpmailerException
      * @access protected
-     * @return bool
+     * @return boolean
      */
     protected function mailSend($header, $body)
     {
         $toArr = array();
-        foreach ($this->to as $t) {
-            $toArr[] = $this->addrFormat($t);
+        foreach ($this->to as $toaddr) {
+            $toArr[] = $this->addrFormat($toaddr);
         }
         $to = implode(', ', $toArr);
 
-        if (empty($this->Sender)) {
-            $params = " ";
-        } else {
-            $params = sprintf("-f%s", $this->Sender);
-        }
-        if ($this->Sender != '' and !ini_get('safe_mode')) {
+        $params = null;
+        //This sets the SMTP envelope sender which gets turned into a return-path header by the receiver
+        if (!empty($this->Sender) and $this->validateAddress($this->Sender)) {
+            // CVE-2016-10033, CVE-2016-10045: Don't pass -f if characters will be escaped.
+            if (self::isShellSafe($this->Sender)) {
+                $params = sprintf('-f%s', $this->Sender);
+            }
+        }
+        if (!empty($this->Sender) and !ini_get('safe_mode') and $this->validateAddress($this->Sender)) {
             $old_from = ini_get('sendmail_from');
             ini_set('sendmail_from', $this->Sender);
         }
-        $rt = false;
-        if ($this->SingleTo === true && count($toArr) > 1) {
-            foreach ($toArr as $val) {
-                $rt = $this->mailPassthru($val, $this->Subject, $body, $header, $params);
-                // implement call back function if it exists
-                $isSent = ($rt == 1) ? 1 : 0;
-                $this->doCallback($isSent, $val, $this->cc, $this->bcc, $this->Subject, $body, $this->From);
+        $result = false;
+        if ($this->SingleTo and count($toArr) > 1) {
+            foreach ($toArr as $toAddr) {
+                $result = $this->mailPassthru($toAddr, $this->Subject, $body, $header, $params);
+                $this->doCallback($result, array($toAddr), $this->cc, $this->bcc, $this->Subject, $body, $this->From);
             }
         } else {
-            $rt = $this->mailPassthru($to, $this->Subject, $body, $header, $params);
-            // implement call back function if it exists
-            $isSent = ($rt == 1) ? 1 : 0;
-            $this->doCallback($isSent, $to, $this->cc, $this->bcc, $this->Subject, $body, $this->From);
+            $result = $this->mailPassthru($to, $this->Subject, $body, $header, $params);
+            $this->doCallback($result, $this->to, $this->cc, $this->bcc, $this->Subject, $body, $this->From);
         }
         if (isset($old_from)) {
             ini_set('sendmail_from', $old_from);
         }
-        if (!$rt) {
+        if (!$result) {
             throw new phpmailerException($this->lang('instantiate'), self::STOP_CRITICAL);
         }
@@ -1136 +1518 @@
     {
         if (!is_object($this->smtp)) {
-            require_once 'class-smtp.php';
+            require_once( 'class-smtp.php' );
             $this->smtp = new SMTP;
         }
@@ -1152 +1534 @@
      * @uses SMTP
      * @access protected
-     * @return bool
+     * @return boolean
      */
     protected function smtpSend($header, $body)
     {
         $bad_rcpt = array();
-
-        if (!$this->smtpConnect()) {
+        if (!$this->smtpConnect($this->SMTPOptions)) {
             throw new phpmailerException($this->lang('smtp_connect_failed'), self::STOP_CRITICAL);
         }
-        $smtp_from = ($this->Sender == '') ? $this->From : $this->Sender;
+        if (!empty($this->Sender) and $this->validateAddress($this->Sender)) {
+            $smtp_from = $this->Sender;
+        } else {
+            $smtp_from = $this->From;
+        }
         if (!$this->smtp->mail($smtp_from)) {
             $this->setError($this->lang('from_failed') . $smtp_from . ' : ' . implode(',', $this->smtp->getError()));
@@ -1167 +1552 @@
         }
 
-        // Attempt to send attach all recipients
-        foreach ($this->to as $to) {
-            if (!$this->smtp->recipient($to[0])) {
-                $bad_rcpt[] = $to[0];
-                $isSent = 0;
-            } else {
-                $isSent = 1;
-            }
-            $this->doCallback($isSent, $to[0], '', '', $this->Subject, $body, $this->From);
-        }
-        foreach ($this->cc as $cc) {
-            if (!$this->smtp->recipient($cc[0])) {
-                $bad_rcpt[] = $cc[0];
-                $isSent = 0;
-            } else {
-                $isSent = 1;
-            }
-            $this->doCallback($isSent, '', $cc[0], '', $this->Subject, $body, $this->From);
-        }
-        foreach ($this->bcc as $bcc) {
-            if (!$this->smtp->recipient($bcc[0])) {
-                $bad_rcpt[] = $bcc[0];
-                $isSent = 0;
-            } else {
-                $isSent = 1;
-            }
-            $this->doCallback($isSent, '', '', $bcc[0], $this->Subject, $body, $this->From);
-        }
-
-        if (count($bad_rcpt) > 0) { //Create error message for any bad addresses
-            throw new phpmailerException($this->lang('recipients_failed') . implode(', ', $bad_rcpt));
-        }
-        if (!$this->smtp->data($header . $body)) {
+        // Attempt to send to all recipients
+        foreach (array($this->to, $this->cc, $this->bcc) as $togroup) {
+            foreach ($togroup as $to) {
+                if (!$this->smtp->recipient($to[0])) {
+                    $error = $this->smtp->getError();
+                    $bad_rcpt[] = array('to' => $to[0], 'error' => $error['detail']);
+                    $isSent = false;
+                } else {
+                    $isSent = true;
+                }
+                $this->doCallback($isSent, array($to[0]), array(), array(), $this->Subject, $body, $this->From);
+            }
+        }
+
+        // Only send the DATA command if we have viable recipients
+        if ((count($this->all_recipients) > count($bad_rcpt)) and !$this->smtp->data($header . $body)) {
             throw new phpmailerException($this->lang('data_not_accepted'), self::STOP_CRITICAL);
         }
-        if ($this->SMTPKeepAlive == true) {
+        if ($this->SMTPKeepAlive) {
             $this->smtp->reset();
         } else {
@@ -1208 +1576 @@
             $this->smtp->close();
         }
+        //Create error message for any bad addresses
+        if (count($bad_rcpt) > 0) {
+            $errstr = '';
+            foreach ($bad_rcpt as $bad) {
+                $errstr .= $bad['to'] . ': ' . $bad['error'];
+            }
+            throw new phpmailerException(
+                $this->lang('recipients_failed') . $errstr,
+                self::STOP_CONTINUE
+            );
+        }
         return true;
     }
@@ -1218 +1597 @@
      * @access public
      * @throws phpmailerException
-     * @return bool
-     */
-    public function smtpConnect($options = array())
+     * @return boolean
+     */
+    public function smtpConnect($options = null)
     {
         if (is_null($this->smtp)) {
@@ -1226 +1605 @@
         }
 
-        //Already connected?
+        //If no options are provided, use whatever is set in the instance
+        if (is_null($options)) {
+            $options = $this->SMTPOptions;
+        }
+
+        // Already connected?
         if ($this->smtp->connected()) {
             return true;
@@ -1235 +1619 @@
         $this->smtp->setDebugOutput($this->Debugoutput);
         $this->smtp->setVerp($this->do_verp);
-        $tls = ($this->SMTPSecure == 'tls');
-        $ssl = ($this->SMTPSecure == 'ssl');
         $hosts = explode(';', $this->Host);
         $lastexception = null;
@@ -1242 +1624 @@
         foreach ($hosts as $hostentry) {
             $hostinfo = array();
-            $host = $hostentry;
+            if (!preg_match('/^((ssl|tls):\/\/)*([a-zA-Z0-9\.-]*):?([0-9]*)$/', trim($hostentry), $hostinfo)) {
+                // Not a valid host entry
+                continue;
+            }
+            // $hostinfo[2]: optional ssl or tls prefix
+            // $hostinfo[3]: the hostname
+            // $hostinfo[4]: optional port number
+            // The host string prefix can temporarily override the current setting for SMTPSecure
+            // If it's not specified, the default value is used
+            $prefix = '';
+            $secure = $this->SMTPSecure;
+            $tls = ($this->SMTPSecure == 'tls');
+            if ('ssl' == $hostinfo[2] or ('' == $hostinfo[2] and 'ssl' == $this->SMTPSecure)) {
+                $prefix = 'ssl://';
+                $tls = false; // Can't have SSL and TLS at the same time
+                $secure = 'ssl';
+            } elseif ($hostinfo[2] == 'tls') {
+                $tls = true;
+                // tls doesn't use a prefix
+                $secure = 'tls';
+            }
+            //Do we need the OpenSSL extension?
+            $sslext = defined('OPENSSL_ALGO_SHA1');
+            if ('tls' === $secure or 'ssl' === $secure) {
+                //Check for an OpenSSL constant rather than using extension_loaded, which is sometimes disabled
+                if (!$sslext) {
+                    throw new phpmailerException($this->lang('extension_missing').'openssl', self::STOP_CRITICAL);
+                }
+            }
+            $host = $hostinfo[3];
             $port = $this->Port;
-            if (preg_match(
-                '/^(.+):([0-9]+)$/',
-                $hostentry,
-                $hostinfo
-            )
-            ) { //If $hostentry contains 'address:port', override default
-                $host = $hostinfo[1];
-                $port = $hostinfo[2];
-            }
-            if ($this->smtp->connect(($ssl ? 'ssl://' : '') . $host, $port, $this->Timeout, $options)) {
+            $tport = (integer)$hostinfo[4];
+            if ($tport > 0 and $tport < 65536) {
+                $port = $tport;
+            }
+            if ($this->smtp->connect($prefix . $host, $port, $this->Timeout, $options)) {
                 try {
                     if ($this->Helo) {
@@ -1261 +1667 @@
                     }
                     $this->smtp->hello($hello);
-
+                    //Automatically enable TLS encryption if:
+                    // * it's not disabled
+                    // * we have openssl extension
+                    // * we are not already using SSL
+                    // * the server offers STARTTLS
+                    if ($this->SMTPAutoTLS and $sslext and $secure != 'ssl' and $this->smtp->getServerExt('STARTTLS')) {
+                        $tls = true;
+                    }
                     if ($tls) {
                         if (!$this->smtp->startTLS()) {
                             throw new phpmailerException($this->lang('connect_host'));
                         }
-                        //We must resend HELO after tls negotiation
+                        // We must resend EHLO after TLS negotiation
                         $this->smtp->hello($hello);
                     }
@@ -1282 +1695 @@
                     }
                     return true;
-                } catch (phpmailerException $e) {
-                    $lastexception = $e;
-                    //We must have connected, but then failed TLS or Auth, so close connection nicely
+                } catch (phpmailerException $exc) {
+                    $lastexception = $exc;
+                    $this->edebug($exc->getMessage());
+                    // We must have connected, but then failed TLS or Auth, so close connection nicely
                     $this->smtp->quit();
                 }
             }
         }
-        //If we get here, all connection attempts have failed, so close connection hard
+        // If we get here, all connection attempts have failed, so close connection hard
         $this->smtp->close();
-        //As we've caught all exceptions, just report whatever the last one was
+        // As we've caught all exceptions, just report whatever the last one was
         if ($this->exceptions and !is_null($lastexception)) {
             throw $lastexception;
@@ -1304 +1718 @@
     public function smtpClose()
     {
-        if ($this->smtp !== null) {
+        if (is_a($this->smtp, 'SMTP')) {
             if ($this->smtp->connected()) {
                 $this->smtp->quit();
@@ -1318 +1732 @@
      * @param string $langcode ISO 639-1 2-character language code (e.g. French is "fr")
      * @param string $lang_path Path to the language file directory, with trailing separator (slash)
-     * @return bool
-     * @access public
-     */
-    public function setLanguage($langcode = 'en', $lang_path = 'language/')
-    {
-        //Define full set of translatable strings
+     * @return boolean
+     * @access public
+     */
+    public function setLanguage($langcode = 'en', $lang_path = '')
+    {
+        // Backwards compatibility for renamed language codes
+        $renamed_langcodes = array(
+            'br' => 'pt_br',
+            'cz' => 'cs',
+            'dk' => 'da',
+            'no' => 'nb',
+            'se' => 'sv',
+        );
+
+        if (isset($renamed_langcodes[$langcode])) {
+            $langcode = $renamed_langcodes[$langcode];
+        }
+
+        // Define full set of translatable strings in English
         $PHPMAILER_LANG = array(
             'authenticate' => 'SMTP Error: Could not authenticate.',
@@ -1335 +1762 @@
             'from_failed' => 'The following From address failed: ',
             'instantiate' => 'Could not instantiate mail function.',
-            'invalid_address' => 'Invalid address',
+            'invalid_address' => 'Invalid address: ',
             'mailer_not_supported' => ' mailer is not supported.',
             'provide_address' => 'You must provide at least one recipient email address.',
@@ -1342 +1769 @@
             'smtp_connect_failed' => 'SMTP connect() failed.',
             'smtp_error' => 'SMTP server error: ',
-            'variable_set' => 'Cannot set or reset variable: '
+            'variable_set' => 'Cannot set or reset variable: ',
+            'extension_missing' => 'Extension missing: '
         );
-        //Overwrite language-specific strings.
-        //This way we'll never have missing translations - no more "language string failed to load"!
-        $l = true;
-        if ($langcode != 'en') { //There is no English translation file
-            $l = @include $lang_path . 'phpmailer.lang-' . $langcode . '.php';
+        if (empty($lang_path)) {
+            // Calculate an absolute path so it can work if CWD is not here
+            $lang_path = dirname(__FILE__). DIRECTORY_SEPARATOR . 'language'. DIRECTORY_SEPARATOR;
+        }
+        //Validate $langcode
+        if (!preg_match('/^[a-z]{2}(?:_[a-zA-Z]{2})?$/', $langcode)) {
+            $langcode = 'en';
+        }
+        $foundlang = true;
+        $lang_file = $lang_path . 'phpmailer.lang-' . $langcode . '.php';
+        // There is no English translation file
+        if ($langcode != 'en') {
+            // Make sure language file path is readable
+            if (!is_readable($lang_file)) {
+                $foundlang = false;
+            } else {
+                // Overwrite language-specific strings.
+                // This way we'll never have missing translation keys.
+                $foundlang = include $lang_file;
+            }
         }
         $this->language = $PHPMAILER_LANG;
-        return ($l == true); //Returns false if language not found
+        return (boolean)$foundlang; // Returns false if language not found
     }
 
@@ -1376 +1819 @@
     {
         $addresses = array();
-        foreach ($addr as $a) {
-            $addresses[] = $this->addrFormat($a);
+        foreach ($addr as $address) {
+            $addresses[] = $this->addrFormat($address);
         }
         return $type . ': ' . implode(', ', $addresses) . $this->LE;
@@ -1394 +1837 @@
             return $this->secureHeader($addr[0]);
         } else {
-            return $this->encodeHeader($this->secureHeader($addr[1]), 'phrase') . " <" . $this->secureHeader(
+            return $this->encodeHeader($this->secureHeader($addr[1]), 'phrase') . ' <' . $this->secureHeader(
                 $addr[0]
-            ) . ">";
+            ) . '>';
         }
     }
@@ -1407 +1850 @@
      * @param string $message The message to wrap
      * @param integer $length The line length to wrap to
-     * @param bool $qp_mode Whether to run in Quoted-Printable mode
+     * @param boolean $qp_mode Whether to run in Quoted-Printable mode
      * @access public
      * @return string
@@ -1413 +1856 @@
     public function wrapText($message, $length, $qp_mode = false)
     {
-        $soft_break = ($qp_mode) ? sprintf(" =%s", $this->LE) : $this->LE;
+        if ($qp_mode) {
+            $soft_break = sprintf(' =%s', $this->LE);
+        } else {
+            $soft_break = $this->LE;
+        }
         // If utf-8 encoding is used, we will need to make sure we don't
         // split multibyte characters when we wrap
-        $is_utf8 = (strtolower($this->CharSet) == "utf-8");
+        $is_utf8 = (strtolower($this->CharSet) == 'utf-8');
         $lelen = strlen($this->LE);
         $crlflen = strlen(self::CRLF);
 
         $message = $this->fixEOL($message);
+        //Remove a trailing line break
         if (substr($message, -$lelen) == $this->LE) {
             $message = substr($message, 0, -$lelen);
         }
 
-        $line = explode($this->LE, $message); // Magic. We know fixEOL uses $LE
+        //Split message into lines
+        $lines = explode($this->LE, $message);
+        //Message will be rebuilt in here
         $message = '';
-        for ($i = 0; $i < count($line); $i++) {
-            $line_part = explode(' ', $line[$i]);
+        foreach ($lines as $line) {
+            $words = explode(' ', $line);
             $buf = '';
-            for ($e = 0; $e < count($line_part); $e++) {
-                $word = $line_part[$e];
+            $firstword = true;
+            foreach ($words as $word) {
                 if ($qp_mode and (strlen($word) > $length)) {
                     $space_left = $length - strlen($buf) - $crlflen;
-                    if ($e != 0) {
+                    if (!$firstword) {
                         if ($space_left > 20) {
                             $len = $space_left;
                             if ($is_utf8) {
                                 $len = $this->utf8CharBoundary($word, $len);
-                            } elseif (substr($word, $len - 1, 1) == "=") {
+                            } elseif (substr($word, $len - 1, 1) == '=') {
                                 $len--;
-                            } elseif (substr($word, $len - 2, 1) == "=") {
+                            } elseif (substr($word, $len - 2, 1) == '=') {
                                 $len -= 2;
                             }
@@ -1447 +1897 @@
                             $word = substr($word, $len);
                             $buf .= ' ' . $part;
-                            $message .= $buf . sprintf("=%s", self::CRLF);
+                            $message .= $buf . sprintf('=%s', self::CRLF);
                         } else {
                             $message .= $buf . $soft_break;
@@ -1460 +1910 @@
                         if ($is_utf8) {
                             $len = $this->utf8CharBoundary($word, $len);
-                        } elseif (substr($word, $len - 1, 1) == "=") {
+                        } elseif (substr($word, $len - 1, 1) == '=') {
                             $len--;
-                        } elseif (substr($word, $len - 2, 1) == "=") {
+                        } elseif (substr($word, $len - 2, 1) == '=') {
                             $len -= 2;
                         }
@@ -1469 +1919 @@
 
                         if (strlen($word) > 0) {
-                            $message .= $part . sprintf("=%s", self::CRLF);
+                            $message .= $part . sprintf('=%s', self::CRLF);
                         } else {
                             $buf = $part;
@@ -1476 +1926 @@
                 } else {
                     $buf_o = $buf;
-                    $buf .= ($e == 0) ? $word : (' ' . $word);
+                    if (!$firstword) {
+                        $buf .= ' ';
+                    }
+                    $buf .= $word;
 
                     if (strlen($buf) > $length and $buf_o != '') {
@@ -1483 +1936 @@
                     }
                 }
+                $firstword = false;
             }
             $message .= $buf . self::CRLF;
@@ -1492 +1946 @@
     /**
      * Find the last character boundary prior to $maxLength in a utf-8
-     * quoted (printable) encoded string.
+     * quoted-printable encoded string.
      * Original written by Colin Brown.
      * @access public
      * @param string $encodedText utf-8 QP text
-     * @param int $maxLength   find last character boundary prior to this length
-     * @return int
+     * @param integer $maxLength Find the last character boundary prior to this length
+     * @return integer
      */
     public function utf8CharBoundary($encodedText, $maxLength)
@@ -1505 +1959 @@
         while (!$foundSplitPos) {
             $lastChunk = substr($encodedText, $maxLength - $lookBack, $lookBack);
-            $encodedCharPos = strpos($lastChunk, "=");
-            if ($encodedCharPos !== false) {
+            $encodedCharPos = strpos($lastChunk, '=');
+            if (false !== $encodedCharPos) {
                 // Found start of encoded character byte within $lookBack block.
                 // Check the encoded byte value (the 2 chars after the '=')
                 $hex = substr($encodedText, $maxLength - $lookBack + $encodedCharPos + 1, 2);
                 $dec = hexdec($hex);
-                if ($dec < 128) { // Single byte character.
+                if ($dec < 128) {
+                    // Single byte character.
                     // If the encoded char was found at pos 0, it will fit
                     // otherwise reduce maxLength to start of the encoded char
-                    $maxLength = ($encodedCharPos == 0) ? $maxLength :
-                        $maxLength - ($lookBack - $encodedCharPos);
+                    if ($encodedCharPos > 0) {
+                        $maxLength = $maxLength - ($lookBack - $encodedCharPos);
+                    }
                     $foundSplitPos = true;
-                } elseif ($dec >= 192) { // First byte of a multi byte character
+                } elseif ($dec >= 192) {
+                    // First byte of a multi byte character
                     // Reduce maxLength to split at start of character
                     $maxLength = $maxLength - ($lookBack - $encodedCharPos);
                     $foundSplitPos = true;
-                } elseif ($dec < 192) { // Middle byte of a multi byte character, look further back
+                } elseif ($dec < 192) {
+                    // Middle byte of a multi byte character, look further back
                     $lookBack += 3;
                 }
@@ -1532 +1990 @@
     }
 
-
-    /**
-     * Set the body wrapping.
+    /**
+     * Apply word wrapping to the message body.
+     * Wraps the message body to the number of chars set in the WordWrap property.
+     * You should only do this to plain-text bodies as wrapping HTML tags may break them.
+     * This is called automatically by createBody(), so you don't need to call it yourself.
      * @access public
      * @return void
@@ -1566 +2026 @@
         $result = '';
 
-        // Set the boundaries
-        $uniq_id = md5(uniqid(time()));
-        $this->boundary[1] = 'b1_' . $uniq_id;
-        $this->boundary[2] = 'b2_' . $uniq_id;
-        $this->boundary[3] = 'b3_' . $uniq_id;
-
         if ($this->MessageDate == '') {
-            $result .= $this->headerLine('Date', self::rfcDate());
+            $this->MessageDate = self::rfcDate();
+        }
+        $result .= $this->headerLine('Date', $this->MessageDate);
+
+        // To be created automatically by mail()
+        if ($this->SingleTo) {
+            if ($this->Mailer != 'mail') {
+                foreach ($this->to as $toaddr) {
+                    $this->SingleToArray[] = $this->addrFormat($toaddr);
+                }
+            }
         } else {
-            $result .= $this->headerLine('Date', $this->MessageDate);
-        }
-
-        if ($this->ReturnPath) {
-            $result .= $this->headerLine('Return-Path', '<' . trim($this->ReturnPath) . '>');
-        } elseif ($this->Sender == '') {
-            $result .= $this->headerLine('Return-Path', '<' . trim($this->From) . '>');
-        } else {
-            $result .= $this->headerLine('Return-Path', '<' . trim($this->Sender) . '>');
-        }
-
-        // To be created automatically by mail()
-        if ($this->Mailer != 'mail') {
-            if ($this->SingleTo === true) {
-                foreach ($this->to as $t) {
-                    $this->SingleToArray[] = $this->addrFormat($t);
-                }
-            } else {
-                if (count($this->to) > 0) {
+            if (count($this->to) > 0) {
+                if ($this->Mailer != 'mail') {
                     $result .= $this->addrAppend('To', $this->to);
-                } elseif (count($this->cc) == 0) {
-                    $result .= $this->headerLine('To', 'undisclosed-recipients:;');
-                }
+                }
+            } elseif (count($this->cc) == 0) {
+                $result .= $this->headerLine('To', 'undisclosed-recipients:;');
             }
         }
@@ -1609 +2056 @@
 
         // sendmail and mail() extract Bcc from the header before sending
-        if ((($this->Mailer == 'sendmail') || ($this->Mailer == 'mail')) && (count($this->bcc) > 0)) {
+        if ((
+                $this->Mailer == 'sendmail' or $this->Mailer == 'qmail' or $this->Mailer == 'mail'
+            )
+            and count($this->bcc) > 0
+        ) {
             $result .= $this->addrAppend('Bcc', $this->bcc);
         }
@@ -1622 +2073 @@
         }
 
-        if ($this->MessageID != '') {
+        // Only allow a custom message ID if it conforms to RFC 5322 section 3.6.4
+        // https://tools.ietf.org/html/rfc5322#section-3.6.4
+        if ('' != $this->MessageID and preg_match('/^<.*@.*>$/', $this->MessageID)) {
             $this->lastMessageID = $this->MessageID;
         } else {
-            $this->lastMessageID = sprintf("<%s@%s>", $uniq_id, $this->ServerHostname());
-        }
-        $result .= $this->HeaderLine('Message-ID', $this->lastMessageID);
-        $result .= $this->headerLine('X-Priority', $this->Priority);
+            $this->lastMessageID = sprintf('<%s@%s>', $this->uniqueid, $this->serverHostname());
+        }
+        $result .= $this->headerLine('Message-ID', $this->lastMessageID);
+        if (!is_null($this->Priority)) {
+            $result .= $this->headerLine('X-Priority', $this->Priority);
+        }
         if ($this->XMailer == '') {
             $result .= $this->headerLine(
                 'X-Mailer',
-                'PHPMailer ' . $this->Version . ' (https://github.com/PHPMailer/PHPMailer/)'
+                'PHPMailer ' . $this->Version . ' (https://github.com/PHPMailer/PHPMailer)'
             );
         } else {
@@ -1642 +2097 @@
 
         if ($this->ConfirmReadingTo != '') {
-            $result .= $this->headerLine('Disposition-Notification-To', '<' . trim($this->ConfirmReadingTo) . '>');
+            $result .= $this->headerLine('Disposition-Notification-To', '<' . $this->ConfirmReadingTo . '>');
         }
 
         // Add custom headers
-        for ($index = 0; $index < count($this->CustomHeader); $index++) {
+        foreach ($this->CustomHeader as $header) {
             $result .= $this->headerLine(
-                trim($this->CustomHeader[$index][0]),
-                $this->encodeHeader(trim($this->CustomHeader[$index][1]))
+                trim($header[0]),
+                $this->encodeHeader(trim($header[1]))
             );
         }
@@ -1668 +2123 @@
     {
         $result = '';
+        $ismultipart = true;
         switch ($this->message_type) {
             case 'inline':
@@ -1688 +2144 @@
                 // Catches case 'plain': and case '':
                 $result .= $this->textLine('Content-Type: ' . $this->ContentType . '; charset=' . $this->CharSet);
+                $ismultipart = false;
                 break;
         }
-        //RFC1341 part 5 says 7bit is assumed if not specified
+        // RFC1341 part 5 says 7bit is assumed if not specified
         if ($this->Encoding != '7bit') {
-            $result .= $this->headerLine('Content-Transfer-Encoding', $this->Encoding);
+            // RFC 2045 section 6.4 says multipart MIME parts may only use 7bit, 8bit or binary CTE
+            if ($ismultipart) {
+                if ($this->Encoding == '8bit') {
+                    $result .= $this->headerLine('Content-Transfer-Encoding', '8bit');
+                }
+                // The only remaining alternatives are quoted-printable and base64, which are both 7bit compatible
+            } else {
+                $result .= $this->headerLine('Content-Transfer-Encoding', $this->Encoding);
+            }
         }
 
@@ -1705 +2170 @@
      * Returns the whole MIME message.
      * Includes complete headers and body.
-     * Only valid post PreSend().
-     * @see PHPMailer::PreSend()
+     * Only valid post preSend().
+     * @see PHPMailer::preSend()
      * @access public
      * @return string
@@ -1712 +2177 @@
     public function getSentMIMEMessage()
     {
-        return $this->MIMEHeader . $this->mailHeader . self::CRLF . $this->MIMEBody;
-    }
-
+        return rtrim($this->MIMEHeader . $this->mailHeader, "\n\r") . self::CRLF . self::CRLF . $this->MIMEBody;
+    }
+
+    /**
+     * Create unique ID
+     * @return string
+     */
+    protected function generateId() {
+        return md5(uniqid(time()));
+    }
 
     /**
@@ -1726 +2198 @@
     {
         $body = '';
+        //Create unique IDs and preset boundaries
+        $this->uniqueid = $this->generateId();
+        $this->boundary[1] = 'b1_' . $this->uniqueid;
+        $this->boundary[2] = 'b2_' . $this->uniqueid;
+        $this->boundary[3] = 'b3_' . $this->uniqueid;
 
         if ($this->sign_key_file) {
@@ -1733 +2210 @@
         $this->setWordWrap();
 
+        $bodyEncoding = $this->Encoding;
+        $bodyCharSet = $this->CharSet;
+        //Can we do a 7-bit downgrade?
+        if ($bodyEncoding == '8bit' and !$this->has8bitChars($this->Body)) {
+            $bodyEncoding = '7bit';
+            //All ISO 8859, Windows codepage and UTF-8 charsets are ascii compatible up to 7-bit
+            $bodyCharSet = 'us-ascii';
+        }
+        //If lines are too long, and we're not already using an encoding that will shorten them,
+        //change to quoted-printable transfer encoding for the body part only
+        if ('base64' != $this->Encoding and self::hasLineLongerThanMax($this->Body)) {
+            $bodyEncoding = 'quoted-printable';
+        }
+
+        $altBodyEncoding = $this->Encoding;
+        $altBodyCharSet = $this->CharSet;
+        //Can we do a 7-bit downgrade?
+        if ($altBodyEncoding == '8bit' and !$this->has8bitChars($this->AltBody)) {
+            $altBodyEncoding = '7bit';
+            //All ISO 8859, Windows codepage and UTF-8 charsets are ascii compatible up to 7-bit
+            $altBodyCharSet = 'us-ascii';
+        }
+        //If lines are too long, and we're not already using an encoding that will shorten them,
+        //change to quoted-printable transfer encoding for the alt body part only
+        if ('base64' != $altBodyEncoding and self::hasLineLongerThanMax($this->AltBody)) {
+            $altBodyEncoding = 'quoted-printable';
+        }
+        //Use this as a preamble in all multipart message types
+        $mimepre = "This is a multi-part message in MIME format." . $this->LE . $this->LE;
         switch ($this->message_type) {
             case 'inline':
-                $body .= $this->getBoundary($this->boundary[1], '', '', '');
-                $body .= $this->encodeString($this->Body, $this->Encoding);
+                $body .= $mimepre;
+                $body .= $this->getBoundary($this->boundary[1], $bodyCharSet, '', $bodyEncoding);
+                $body .= $this->encodeString($this->Body, $bodyEncoding);
                 $body .= $this->LE . $this->LE;
                 $body .= $this->attachAll('inline', $this->boundary[1]);
                 break;
             case 'attach':
-                $body .= $this->getBoundary($this->boundary[1], '', '', '');
-                $body .= $this->encodeString($this->Body, $this->Encoding);
+                $body .= $mimepre;
+                $body .= $this->getBoundary($this->boundary[1], $bodyCharSet, '', $bodyEncoding);
+                $body .= $this->encodeString($this->Body, $bodyEncoding);
                 $body .= $this->LE . $this->LE;
                 $body .= $this->attachAll('attachment', $this->boundary[1]);
                 break;
             case 'inline_attach':
+                $body .= $mimepre;
                 $body .= $this->textLine('--' . $this->boundary[1]);
                 $body .= $this->headerLine('Content-Type', 'multipart/related;');
                 $body .= $this->textLine("\tboundary=\"" . $this->boundary[2] . '"');
                 $body .= $this->LE;
-                $body .= $this->getBoundary($this->boundary[2], '', '', '');
-                $body .= $this->encodeString($this->Body, $this->Encoding);
+                $body .= $this->getBoundary($this->boundary[2], $bodyCharSet, '', $bodyEncoding);
+                $body .= $this->encodeString($this->Body, $bodyEncoding);
                 $body .= $this->LE . $this->LE;
                 $body .= $this->attachAll('inline', $this->boundary[2]);
@@ -1759 +2268 @@
                 break;
             case 'alt':
-                $body .= $this->getBoundary($this->boundary[1], '', 'text/plain', '');
-                $body .= $this->encodeString($this->AltBody, $this->Encoding);
+                $body .= $mimepre;
+                $body .= $this->getBoundary($this->boundary[1], $altBodyCharSet, 'text/plain', $altBodyEncoding);
+                $body .= $this->encodeString($this->AltBody, $altBodyEncoding);
                 $body .= $this->LE . $this->LE;
-                $body .= $this->getBoundary($this->boundary[1], '', 'text/html', '');
-                $body .= $this->encodeString($this->Body, $this->Encoding);
+                $body .= $this->getBoundary($this->boundary[1], $bodyCharSet, 'text/html', $bodyEncoding);
+                $body .= $this->encodeString($this->Body, $bodyEncoding);
                 $body .= $this->LE . $this->LE;
                 if (!empty($this->Ical)) {
@@ -1773 +2283 @@
                 break;
             case 'alt_inline':
-                $body .= $this->getBoundary($this->boundary[1], '', 'text/plain', '');
-                $body .= $this->encodeString($this->AltBody, $this->Encoding);
+                $body .= $mimepre;
+                $body .= $this->getBoundary($this->boundary[1], $altBodyCharSet, 'text/plain', $altBodyEncoding);
+                $body .= $this->encodeString($this->AltBody, $altBodyEncoding);
                 $body .= $this->LE . $this->LE;
                 $body .= $this->textLine('--' . $this->boundary[1]);
@@ -1780 +2291 @@
                 $body .= $this->textLine("\tboundary=\"" . $this->boundary[2] . '"');
                 $body .= $this->LE;
-                $body .= $this->getBoundary($this->boundary[2], '', 'text/html', '');
-                $body .= $this->encodeString($this->Body, $this->Encoding);
+                $body .= $this->getBoundary($this->boundary[2], $bodyCharSet, 'text/html', $bodyEncoding);
+                $body .= $this->encodeString($this->Body, $bodyEncoding);
                 $body .= $this->LE . $this->LE;
                 $body .= $this->attachAll('inline', $this->boundary[2]);
@@ -1788 +2299 @@
                 break;
             case 'alt_attach':
+                $body .= $mimepre;
                 $body .= $this->textLine('--' . $this->boundary[1]);
                 $body .= $this->headerLine('Content-Type', 'multipart/alternative;');
                 $body .= $this->textLine("\tboundary=\"" . $this->boundary[2] . '"');
                 $body .= $this->LE;
-                $body .= $this->getBoundary($this->boundary[2], '', 'text/plain', '');
-                $body .= $this->encodeString($this->AltBody, $this->Encoding);
+                $body .= $this->getBoundary($this->boundary[2], $altBodyCharSet, 'text/plain', $altBodyEncoding);
+                $body .= $this->encodeString($this->AltBody, $altBodyEncoding);
                 $body .= $this->LE . $this->LE;
-                $body .= $this->getBoundary($this->boundary[2], '', 'text/html', '');
-                $body .= $this->encodeString($this->Body, $this->Encoding);
+                $body .= $this->getBoundary($this->boundary[2], $bodyCharSet, 'text/html', $bodyEncoding);
+                $body .= $this->encodeString($this->Body, $bodyEncoding);
                 $body .= $this->LE . $this->LE;
                 $body .= $this->endBoundary($this->boundary[2]);
@@ -1803 +2315 @@
                 break;
             case 'alt_inline_attach':
+                $body .= $mimepre;
                 $body .= $this->textLine('--' . $this->boundary[1]);
                 $body .= $this->headerLine('Content-Type', 'multipart/alternative;');
                 $body .= $this->textLine("\tboundary=\"" . $this->boundary[2] . '"');
                 $body .= $this->LE;
-                $body .= $this->getBoundary($this->boundary[2], '', 'text/plain', '');
-                $body .= $this->encodeString($this->AltBody, $this->Encoding);
+                $body .= $this->getBoundary($this->boundary[2], $altBodyCharSet, 'text/plain', $altBodyEncoding);
+                $body .= $this->encodeString($this->AltBody, $altBodyEncoding);
                 $body .= $this->LE . $this->LE;
                 $body .= $this->textLine('--' . $this->boundary[2]);
@@ -1814 +2327 @@
                 $body .= $this->textLine("\tboundary=\"" . $this->boundary[3] . '"');
                 $body .= $this->LE;
-                $body .= $this->getBoundary($this->boundary[3], '', 'text/html', '');
-                $body .= $this->encodeString($this->Body, $this->Encoding);
+                $body .= $this->getBoundary($this->boundary[3], $bodyCharSet, 'text/html', $bodyEncoding);
+                $body .= $this->encodeString($this->Body, $bodyEncoding);
                 $body .= $this->LE . $this->LE;
                 $body .= $this->attachAll('inline', $this->boundary[3]);
@@ -1824 +2337 @@
                 break;
             default:
-                // catch case 'plain' and case ''
+                // Catch case 'plain' and case '', applies to simple `text/plain` and `text/html` body content types
+                //Reset the `Encoding` property in case we changed it for line length reasons
+                $this->Encoding = $bodyEncoding;
                 $body .= $this->encodeString($this->Body, $this->Encoding);
                 break;
@@ -1834 +2349 @@
             try {
                 if (!defined('PKCS7_TEXT')) {
-                    throw new phpmailerException($this->lang('signing') . ' OpenSSL extension missing.');
-                }
+                    throw new phpmailerException($this->lang('extension_missing') . 'openssl');
+                }
+                // @TODO would be nice to use php://temp streams here, but need to wrap for PHP < 5.1
                 $file = tempnam(sys_get_temp_dir(), 'mail');
-                file_put_contents($file, $body); //TODO check this worked
+                if (false === file_put_contents($file, $body)) {
+                    throw new phpmailerException($this->lang('signing') . ' Could not write temp file');
+                }
                 $signed = tempnam(sys_get_temp_dir(), 'signed');
-                if (@openssl_pkcs7_sign(
-                    $file,
-                    $signed,
-                    'file://' . realpath($this->sign_cert_file),
-                    array('file://' . realpath($this->sign_key_file), $this->sign_key_pass),
-                    null
-                )
-                ) {
+                //Workaround for PHP bug https://bugs.php.net/bug.php?id=69197
+                if (empty($this->sign_extracerts_file)) {
+                    $sign = @openssl_pkcs7_sign(
+                        $file,
+                        $signed,
+                        'file://' . realpath($this->sign_cert_file),
+                        array('file://' . realpath($this->sign_key_file), $this->sign_key_pass),
+                        null
+                    );
+                } else {
+                    $sign = @openssl_pkcs7_sign(
+                        $file,
+                        $signed,
+                        'file://' . realpath($this->sign_cert_file),
+                        array('file://' . realpath($this->sign_key_file), $this->sign_key_pass),
+                        null,
+                        PKCS7_DETACHED,
+                        $this->sign_extracerts_file
+                    );
+                }
+                if ($sign) {
                     @unlink($file);
                     $body = file_get_contents($signed);
                     @unlink($signed);
+                    //The message returned by openssl contains both headers and body, so need to split them up
+                    $parts = explode("\n\n", $body, 2);
+                    $this->MIMEHeader .= $parts[0] . $this->LE . $this->LE;
+                    $body = $parts[1];
                 } else {
                     @unlink($file);
@@ -1855 +2390 @@
                     throw new phpmailerException($this->lang('signing') . openssl_error_string());
                 }
-            } catch (phpmailerException $e) {
+            } catch (phpmailerException $exc) {
                 $body = '';
                 if ($this->exceptions) {
-                    throw $e;
+                    throw $exc;
                 }
             }
@@ -1887 +2422 @@
         }
         $result .= $this->textLine('--' . $boundary);
-        $result .= sprintf("Content-Type: %s; charset=%s", $contentType, $charSet);
+        $result .= sprintf('Content-Type: %s; charset=%s', $contentType, $charSet);
         $result .= $this->LE;
-        $result .= $this->headerLine('Content-Transfer-Encoding', $encoding);
+        // RFC1341 part 5 says 7bit is assumed if not specified
+        if ($encoding != '7bit') {
+            $result .= $this->headerLine('Content-Transfer-Encoding', $encoding);
+        }
         $result .= $this->LE;
 
@@ -1908 +2446 @@
     /**
      * Set the message type.
-     * PHPMailer only supports some preset message types,
-     * not arbitrary MIME structures.
+     * PHPMailer only supports some preset message types, not arbitrary MIME structures.
      * @access protected
      * @return void
@@ -1915 +2452 @@
     protected function setMessageType()
     {
-        $this->message_type = array();
+        $type = array();
         if ($this->alternativeExists()) {
-            $this->message_type[] = "alt";
+            $type[] = 'alt';
         }
         if ($this->inlineImageExists()) {
-            $this->message_type[] = "inline";
+            $type[] = 'inline';
         }
         if ($this->attachmentExists()) {
-            $this->message_type[] = "attach";
-        }
-        $this->message_type = implode("_", $this->message_type);
-        if ($this->message_type == "") {
-            $this->message_type = "plain";
+            $type[] = 'attach';
+        }
+        $this->message_type = implode('_', $type);
+        if ($this->message_type == '') {
+            //The 'plain' message_type refers to the message having a single body element, not that it is plain-text
+            $this->message_type = 'plain';
         }
     }
@@ -1963 +2501 @@
      * @param string $disposition Disposition to use
      * @throws phpmailerException
-     * @return bool
+     * @return boolean
      */
     public function addAttachment($path, $name = '', $encoding = 'base64', $type = '', $disposition = 'attachment')
@@ -1972 +2510 @@
             }
 
-            //If a MIME type is not specified, try to work it out from the file name
+            // If a MIME type is not specified, try to work it out from the file name
             if ($type == '') {
                 $type = self::filenameToType($path);
@@ -1993 +2531 @@
             );
 
-        } catch (phpmailerException $e) {
-            $this->setError($e->getMessage());
+        } catch (phpmailerException $exc) {
+            $this->setError($exc->getMessage());
+            $this->edebug($exc->getMessage());
             if ($this->exceptions) {
-                throw $e;
-            }
-            $this->edebug($e->getMessage() . "\n");
+                throw $exc;
+            }
             return false;
         }
@@ -2052 +2590 @@
                 $disposition = $attachment[6];
                 $cid = $attachment[7];
-                if ($disposition == 'inline' && isset($cidUniq[$cid])) {
+                if ($disposition == 'inline' && array_key_exists($cid, $cidUniq)) {
                     continue;
                 }
                 $cidUniq[$cid] = true;
 
-                $mime[] = sprintf("--%s%s", $boundary, $this->LE);
-                $mime[] = sprintf(
-                    "Content-Type: %s; name=\"%s\"%s",
-                    $type,
-                    $this->encodeHeader($this->secureHeader($name)),
-                    $this->LE
-                );
-                $mime[] = sprintf("Content-Transfer-Encoding: %s%s", $encoding, $this->LE);
+                $mime[] = sprintf('--%s%s', $boundary, $this->LE);
+                //Only include a filename property if we have one
+                if (!empty($name)) {
+                    $mime[] = sprintf(
+                        'Content-Type: %s; name="%s"%s',
+                        $type,
+                        $this->encodeHeader($this->secureHeader($name)),
+                        $this->LE
+                    );
+                } else {
+                    $mime[] = sprintf(
+                        'Content-Type: %s%s',
+                        $type,
+                        $this->LE
+                    );
+                }
+                // RFC1341 part 5 says 7bit is assumed if not specified
+                if ($encoding != '7bit') {
+                    $mime[] = sprintf('Content-Transfer-Encoding: %s%s', $encoding, $this->LE);
+                }
 
                 if ($disposition == 'inline') {
-                    $mime[] = sprintf("Content-ID: <%s>%s", $cid, $this->LE);
+                    $mime[] = sprintf('Content-ID: <%s>%s', $cid, $this->LE);
                 }
 
@@ -2075 +2625 @@
                 // Allow for bypassing the Content-Disposition header totally
                 if (!(empty($disposition))) {
-                    if (preg_match('/[ \(\)<>@,;:\\"\/\[\]\?=]/', $name)) {
+                    $encoded_name = $this->encodeHeader($this->secureHeader($name));
+                    if (preg_match('/[ \(\)<>@,;:\\"\/\[\]\?=]/', $encoded_name)) {
                         $mime[] = sprintf(
-                            "Content-Disposition: %s; filename=\"%s\"%s",
+                            'Content-Disposition: %s; filename="%s"%s',
                             $disposition,
-                            $this->encodeHeader($this->secureHeader($name)),
+                            $encoded_name,
                             $this->LE . $this->LE
                         );
                     } else {
-                        $mime[] = sprintf(
-                            "Content-Disposition: %s; filename=%s%s",
-                            $disposition,
-                            $this->encodeHeader($this->secureHeader($name)),
-                            $this->LE . $this->LE
-                        );
+                        if (!empty($encoded_name)) {
+                            $mime[] = sprintf(
+                                'Content-Disposition: %s; filename=%s%s',
+                                $disposition,
+                                $encoded_name,
+                                $this->LE . $this->LE
+                            );
+                        } else {
+                            $mime[] = sprintf(
+                                'Content-Disposition: %s%s',
+                                $disposition,
+                                $this->LE . $this->LE
+                            );
+                        }
                     }
                 } else {
@@ -2111 +2670 @@
         }
 
-        $mime[] = sprintf("--%s--%s", $boundary, $this->LE);
-
-        return implode("", $mime);
+        $mime[] = sprintf('--%s--%s', $boundary, $this->LE);
+
+        return implode('', $mime);
     }
 
@@ -2122 +2681 @@
      * @param string $encoding The encoding to use; one of 'base64', '7bit', '8bit', 'binary', 'quoted-printable'
      * @throws phpmailerException
-     * @see EncodeFile(encodeFile
      * @access protected
      * @return string
@@ -2135 +2693 @@
             if ($magic_quotes) {
                 if (version_compare(PHP_VERSION, '5.3.0', '<')) {
-                    set_magic_quotes_runtime(0);
+                    set_magic_quotes_runtime(false);
                 } else {
-                    ini_set('magic_quotes_runtime', 0);
+                    //Doesn't exist in PHP 5.4, but we don't need to check because
+                    //get_magic_quotes_runtime always returns false in 5.4+
+                    //so it will never get here
+                    ini_set('magic_quotes_runtime', false);
                 }
             }
@@ -2150 +2711 @@
             }
             return $file_buffer;
-        } catch (Exception $e) {
-            $this->setError($e->getMessage());
+        } catch (Exception $exc) {
+            $this->setError($exc->getMessage());
             return '';
         }
@@ -2174 +2735 @@
             case '8bit':
                 $encoded = $this->fixEOL($str);
-                //Make sure it ends with a line break
+                // Make sure it ends with a line break
                 if (substr($encoded, -(strlen($this->LE))) != $this->LE) {
                     $encoded .= $this->LE;
@@ -2202 +2763 @@
     public function encodeHeader($str, $position = 'text')
     {
-        $x = 0;
+        $matchcount = 0;
         switch (strtolower($position)) {
             case 'phrase':
                 if (!preg_match('/[\200-\377]/', $str)) {
-                    // Can't use addslashes as we don't know what value has magic_quotes_sybase
+                    // Can't use addslashes as we don't know the value of magic_quotes_sybase
                     $encoded = addcslashes($str, "\0..\37\177\\\"");
                     if (($str == $encoded) && !preg_match('/[^A-Za-z0-9!#$%&\'*+\/=?^_`{|}~ -]/', $str)) {
@@ -2214 +2775 @@
                     }
                 }
-                $x = preg_match_all('/[^\040\041\043-\133\135-\176]/', $str, $matches);
+                $matchcount = preg_match_all('/[^\040\041\043-\133\135-\176]/', $str, $matches);
                 break;
             /** @noinspection PhpMissingBreakStatementInspection */
             case 'comment':
-                $x = preg_match_all('/[()"]/', $str, $matches);
+                $matchcount = preg_match_all('/[()"]/', $str, $matches);
                 // Intentional fall-through
             case 'text':
             default:
-                $x += preg_match_all('/[\000-\010\013\014\016-\037\177-\377]/', $str, $matches);
+                $matchcount += preg_match_all('/[\000-\010\013\014\016-\037\177-\377]/', $str, $matches);
                 break;
         }
 
-        if ($x == 0) { //There are no chars that need encoding
+        //There are no chars that need encoding
+        if ($matchcount == 0) {
             return ($str);
         }
@@ -2232 +2794 @@
         $maxlen = 75 - 7 - strlen($this->CharSet);
         // Try to select the encoding which should produce the shortest output
-        if ($x > strlen($str) / 3) {
-            //More than a third of the content will need encoding, so B encoding will be most efficient
+        if ($matchcount > strlen($str) / 3) {
+            // More than a third of the content will need encoding, so B encoding will be most efficient
             $encoding = 'B';
             if (function_exists('mb_strlen') && $this->hasMultiBytes($str)) {
@@ -2251 +2813 @@
         }
 
-        $encoded = preg_replace('/^(.*)$/m', " =?" . $this->CharSet . "?$encoding?\\1?=", $encoded);
+        $encoded = preg_replace('/^(.*)$/m', ' =?' . $this->CharSet . "?$encoding?\\1?=", $encoded);
         $encoded = trim(str_replace("\n", $this->LE, $encoded));
 
@@ -2261 +2823 @@
      * @access public
      * @param string $str multi-byte text to wrap encode
-     * @return bool
+     * @return boolean
      */
     public function hasMultiBytes($str)
@@ -2273 +2835 @@
 
     /**
+     * Does a string contain any 8-bit chars (in any charset)?
+     * @param string $text
+     * @return boolean
+     */
+    public function has8bitChars($text)
+    {
+        return (boolean)preg_match('/[\x80-\xFF]/', $text);
+    }
+
+    /**
      * Encode and wrap long multibyte strings for mail headers
      * without breaking lines within a character.
-     * Adapted from a function by paravoid at http://uk.php.net/manual/en/function.mb-encode-mimeheader.php
+     * Adapted from a function by paravoid
+     * @link http://www.php.net/manual/en/function.mb-encode-mimeheader.php#60283
      * @access public
      * @param string $str multi-byte text to wrap encode
-     * @param string $lf string to use as linefeed/end-of-line
+     * @param string $linebreak string to use as linefeed/end-of-line
      * @return string
      */
-    public function base64EncodeWrapMB($str, $lf = null)
-    {
-        $start = "=?" . $this->CharSet . "?B?";
-        $end = "?=";
-        $encoded = "";
-        if ($lf === null) {
-            $lf = $this->LE;
+    public function base64EncodeWrapMB($str, $linebreak = null)
+    {
+        $start = '=?' . $this->CharSet . '?B?';
+        $end = '?=';
+        $encoded = '';
+        if ($linebreak === null) {
+            $linebreak = $this->LE;
         }
 
@@ -2306 +2879 @@
                 $lookBack++;
             } while (strlen($chunk) > $length);
-            $encoded .= $chunk . $lf;
+            $encoded .= $chunk . $linebreak;
         }
 
         // Chomp the last linefeed
-        $encoded = substr($encoded, 0, -strlen($lf));
+        $encoded = substr($encoded, 0, -strlen($linebreak));
         return $encoded;
     }
@@ -2321 +2894 @@
      * @param integer $line_max Number of chars allowed on a line before wrapping
      * @return string
-     * @link PHP version adapted from http://www.php.net/manual/en/function.quoted-printable-decode.php#89417
+     * @link http://www.php.net/manual/en/function.quoted-printable-decode.php#89417 Adapted from this comment
      */
     public function encodeQP($string, $line_max = 76)
     {
-        if (function_exists('quoted_printable_encode')) { //Use native function if it's available (>= PHP5.3)
+        // Use native function if it's available (>= PHP5.3)
+        if (function_exists('quoted_printable_encode')) {
             return quoted_printable_encode($string);
         }
-        //Fall back to a pure PHP implementation
+        // Fall back to a pure PHP implementation
         $string = str_replace(
             array('%20', '%0D%0A.', '%0D%0A', '%'),
@@ -2334 +2908 @@
             rawurlencode($string)
         );
-        $string = preg_replace('/[^\r\n]{' . ($line_max - 3) . '}[^=\r\n]{2}/', "$0=\r\n", $string);
-        return $string;
+        return preg_replace('/[^\r\n]{' . ($line_max - 3) . '}[^=\r\n]{2}/', "$0=\r\n", $string);
     }
 
@@ -2344 +2917 @@
      * @param string $string
      * @param integer $line_max
-     * @param bool $space_conv
+     * @param boolean $space_conv
      * @return string
      * @deprecated Use encodeQP instead.
@@ -2366 +2939 @@
     public function encodeQ($str, $position = 'text')
     {
-        //There should not be any EOL in the string
+        // There should not be any EOL in the string
         $pattern = '';
         $encoded = str_replace(array("\r", "\n"), '', $str);
         switch (strtolower($position)) {
             case 'phrase':
-                //RFC 2047 section 5.3
+                // RFC 2047 section 5.3
                 $pattern = '^A-Za-z0-9!*+\/ -';
                 break;
             /** @noinspection PhpMissingBreakStatementInspection */
             case 'comment':
-                //RFC 2047 section 5.2
+                // RFC 2047 section 5.2
                 $pattern = '\(\)"';
-                //intentional fall-through
-                //for this reason we build the $pattern without including delimiters and []
+                // intentional fall-through
+                // for this reason we build the $pattern without including delimiters and []
             case 'text':
             default:
-                //RFC 2047 section 5.1
-                //Replace every high ascii, control, =, ? and _ characters
+                // RFC 2047 section 5.1
+                // Replace every high ascii, control, =, ? and _ characters
                 $pattern = '\000-\011\013\014\016-\037\075\077\137\177-\377' . $pattern;
                 break;
@@ -2389 +2962 @@
         $matches = array();
         if (preg_match_all("/[{$pattern}]/", $encoded, $matches)) {
-            //If the string contains an '=', make sure it's the first thing we replace
-            //so as to avoid double-encoding
-            $s = array_search('=', $matches[0]);
-            if ($s !== false) {
-                unset($matches[0][$s]);
+            // If the string contains an '=', make sure it's the first thing we replace
+            // so as to avoid double-encoding
+            $eqkey = array_search('=', $matches[0]);
+            if (false !== $eqkey) {
+                unset($matches[0][$eqkey]);
                 array_unshift($matches[0], '=');
             }
@@ -2400 +2973 @@
             }
         }
-        //Replace every spaces to _ (more readable than =20)
+        // Replace every spaces to _ (more readable than =20)
         return str_replace(' ', '_', $encoded);
     }
-
 
     /**
@@ -2423 +2995 @@
         $disposition = 'attachment'
     ) {
-        //If a MIME type is not specified, try to work it out from the file name
+        // If a MIME type is not specified, try to work it out from the file name
         if ($type == '') {
             $type = self::filenameToType($filename);
@@ -2443 +3015 @@
      * Add an embedded (inline) attachment from a file.
      * This can include images, sounds, and just about any other document type.
-     * These differ from 'regular' attachmants in that they are intended to be
+     * These differ from 'regular' attachments in that they are intended to be
      * displayed inline with the message, not just attached for download.
      * This is used in HTML messages that embed the images
@@ -2454 +3026 @@
      * @param string $type File MIME type.
      * @param string $disposition Disposition to use
-     * @return bool True on successfully adding an attachment
+     * @return boolean True on successfully adding an attachment
      */
     public function addEmbeddedImage($path, $cid, $name = '', $encoding = 'base64', $type = '', $disposition = 'inline')
@@ -2463 +3035 @@
         }
 
-        //If a MIME type is not specified, try to work it out from the file name
+        // If a MIME type is not specified, try to work it out from the file name
         if ($type == '') {
             $type = self::filenameToType($path);
@@ -2499 +3071 @@
      * @param string $type MIME type.
      * @param string $disposition Disposition to use
-     * @return bool True on successfully adding an attachment
+     * @return boolean True on successfully adding an attachment
      */
     public function addStringEmbeddedImage(
@@ -2509 +3081 @@
         $disposition = 'inline'
     ) {
-        //If a MIME type is not specified, try to work it out from the name
-        if ($type == '') {
+        // If a MIME type is not specified, try to work it out from the name
+        if ($type == '' and !empty($name)) {
             $type = self::filenameToType($name);
         }
@@ -2531 +3103 @@
      * Check if an inline attachment is present.
      * @access public
-     * @return bool
+     * @return boolean
      */
     public function inlineImageExists()
@@ -2545 +3117 @@
     /**
      * Check if an attachment (non-inline) is present.
-     * @return bool
+     * @return boolean
      */
     public function attachmentExists()
@@ -2559 +3131 @@
     /**
      * Check if this message has an alternative body set.
-     * @return bool
+     * @return boolean
      */
     public function alternativeExists()
     {
         return !empty($this->AltBody);
+    }
+
+    /**
+     * Clear queued addresses of given kind.
+     * @access protected
+     * @param string $kind 'to', 'cc', or 'bcc'
+     * @return void
+     */
+    public function clearQueuedAddresses($kind)
+    {
+        $RecipientsQueue = $this->RecipientsQueue;
+        foreach ($RecipientsQueue as $address => $params) {
+            if ($params[0] == $kind) {
+                unset($this->RecipientsQueue[$address]);
+            }
+        }
     }
 
@@ -2576 +3164 @@
         }
         $this->to = array();
+        $this->clearQueuedAddresses('to');
     }
 
@@ -2588 +3177 @@
         }
         $this->cc = array();
+        $this->clearQueuedAddresses('cc');
     }
 
@@ -2600 +3190 @@
         }
         $this->bcc = array();
+        $this->clearQueuedAddresses('bcc');
     }
 
@@ -2609 +3200 @@
     {
         $this->ReplyTo = array();
+        $this->ReplyToQueue = array();
     }
 
@@ -2621 +3213 @@
         $this->bcc = array();
         $this->all_recipients = array();
+        $this->RecipientsQueue = array();
     }
 
@@ -2652 +3245 @@
         if ($this->Mailer == 'smtp' and !is_null($this->smtp)) {
             $lasterror = $this->smtp->getError();
-            if (!empty($lasterror) and array_key_exists('smtp_msg', $lasterror)) {
-                $msg .= '<p>' . $this->lang('smtp_error') . $lasterror['smtp_msg'] . "</p>\n";
+            if (!empty($lasterror['error'])) {
+                $msg .= $this->lang('smtp_error') . $lasterror['error'];
+                if (!empty($lasterror['detail'])) {
+                    $msg .= ' Detail: '. $lasterror['detail'];
+                }
+                if (!empty($lasterror['smtp_code'])) {
+                    $msg .= ' SMTP code: ' . $lasterror['smtp_code'];
+                }
+                if (!empty($lasterror['smtp_code_ex'])) {
+                    $msg .= ' Additional SMTP info: ' . $lasterror['smtp_code_ex'];
+                }
             }
         }
@@ -2667 +3269 @@
     public static function rfcDate()
     {
-        //Set the time zone to whatever the default is to avoid 500 errors
-        //Will default to UTC if it's not set properly in php.ini
+        // Set the time zone to whatever the default is to avoid 500 errors
+        // Will default to UTC if it's not set properly in php.ini
         date_default_timezone_set(@date_default_timezone_get());
         return date('D, j M Y H:i:s O');
@@ -2681 +3283 @@
     protected function serverHostname()
     {
+        $result = 'localhost.localdomain';
         if (!empty($this->Hostname)) {
             $result = $this->Hostname;
-        } elseif (isset($_SERVER['SERVER_NAME'])) {
+        } elseif (isset($_SERVER) and array_key_exists('SERVER_NAME', $_SERVER) and !empty($_SERVER['SERVER_NAME'])) {
             $result = $_SERVER['SERVER_NAME'];
-        } else {
-            $result = 'localhost.localdomain';
-        }
-
+        } elseif (function_exists('gethostname') && gethostname() !== false) {
+            $result = gethostname();
+        } elseif (php_uname('n') !== false) {
+            $result = php_uname('n');
+        }
         return $result;
     }
@@ -2704 +3308 @@
         }
 
-        if (isset($this->language[$key])) {
+        if (array_key_exists($key, $this->language)) {
+            if ($key == 'smtp_connect_failed') {
+                //Include a link to troubleshooting docs on SMTP connection failure
+                //this is by far the biggest cause of support questions
+                //but it's usually not PHPMailer's fault.
+                return $this->language[$key] . ' https://github.com/PHPMailer/PHPMailer/wiki/Troubleshooting';
+            }
             return $this->language[$key];
         } else {
-            return 'Language string failed to load: ' . $key;
+            //Return the key as a fallback
+            return $key;
         }
     }
@@ -2714 +3325 @@
      * Check if an error occurred.
      * @access public
-     * @return bool True if an error did occur.
+     * @return boolean True if an error did occur.
      */
     public function isError()
@@ -2759 +3370 @@
 
     /**
-     * Create a message from an HTML string.
-     * Automatically makes modifications for inline images and backgrounds
-     * and creates a plain-text version by converting the HTML.
-     * Overwrites any existing values in $this->Body and $this->AltBody
+     * Returns all custom headers.
+     * @return array
+     */
+    public function getCustomHeaders()
+    {
+        return $this->CustomHeader;
+    }
+
+    /**
+     * Create a message body from an HTML string.
+     * Automatically inlines images and creates a plain-text version by converting the HTML,
+     * overwriting any existing values in Body and AltBody.
+     * $basedir is used when handling relative image paths, e.g. <img src="images/a.png">
+     * will look for an image file in $basedir/images/a.png and convert it to inline.
+     * If you don't want to apply these transformations to your HTML, just set Body and AltBody yourself.
      * @access public
      * @param string $message HTML message string
-     * @param string $basedir baseline directory for path
-     * @param bool $advanced Whether to use the advanced HTML to text converter
-     * @return string $message
+     * @param string $basedir base directory for relative paths to images
+     * @param boolean|callable $advanced Whether to use the internal HTML to text converter
+     *    or your own custom converter @see PHPMailer::html2text()
+     * @return string $message The transformed message Body
      */
     public function msgHTML($message, $basedir = '', $advanced = false)
     {
-        preg_match_all("/(src|background)=[\"'](.*)[\"']/Ui", $message, $images);
-        if (isset($images[2])) {
-            foreach ($images[2] as $i => $url) {
-                // do not change urls for absolute images (thanks to corvuscorax)
-                if (!preg_match('#^[A-z]+://#', $url)) {
+        preg_match_all('/(src|background)=["\'](.*)["\']/Ui', $message, $images);
+        if (array_key_exists(2, $images)) {
+            foreach ($images[2] as $imgindex => $url) {
+                // Convert data URIs into embedded images
+                if (preg_match('#^data:(image[^;,]*)(;base64)?,#', $url, $match)) {
+                    $data = substr($url, strpos($url, ','));
+                    if ($match[2]) {
+                        $data = base64_decode($data);
+                    } else {
+                        $data = rawurldecode($data);
+                    }
+                    $cid = md5($url) . '@phpmailer.0'; // RFC2392 S 2
+                    if ($this->addStringEmbeddedImage($data, $cid, 'embed' . $imgindex, 'base64', $match[1])) {
+                        $message = str_replace(
+                            $images[0][$imgindex],
+                            $images[1][$imgindex] . '="cid:' . $cid . '"',
+                            $message
+                        );
+                    }
+                } elseif (substr($url, 0, 4) !== 'cid:' && !preg_match('#^[a-z][a-z0-9+.-]*://#i', $url)) {
+                    // Do not change urls for absolute images (thanks to corvuscorax)
+                    // Do not change urls that are already inline images
                     $filename = basename($url);
                     $directory = dirname($url);
@@ -2781 +3421 @@
                         $directory = '';
                     }
-                    $cid = md5($url) . '@phpmailer.0'; //RFC2392 S 2
+                    $cid = md5($url) . '@phpmailer.0'; // RFC2392 S 2
                     if (strlen($basedir) > 1 && substr($basedir, -1) != '/') {
                         $basedir .= '/';
@@ -2793 +3433 @@
                         $filename,
                         'base64',
-                        self::_mime_types(self::mb_pathinfo($filename, PATHINFO_EXTENSION))
+                        self::_mime_types((string)self::mb_pathinfo($filename, PATHINFO_EXTENSION))
                     )
                     ) {
                         $message = preg_replace(
-                            "/" . $images[1][$i] . "=[\"']" . preg_quote($url, '/') . "[\"']/Ui",
-                            $images[1][$i] . "=\"cid:" . $cid . "\"",
+                            '/' . $images[1][$imgindex] . '=["\']' . preg_quote($url, '/') . '["\']/Ui',
+                            $images[1][$imgindex] . '="cid:' . $cid . '"',
                             $message
                         );
@@ -2806 +3446 @@
         }
         $this->isHTML(true);
-        if (empty($this->AltBody)) {
-            $this->AltBody = 'To view this email message, open it in a program that understands HTML!' . "\n\n";
-        }
-        //Convert all message body line breaks to CRLF, makes quoted-printable encoding work much better
+        // Convert all message body line breaks to CRLF, makes quoted-printable encoding work much better
         $this->Body = $this->normalizeBreaks($message);
         $this->AltBody = $this->normalizeBreaks($this->html2text($message, $advanced));
+        if (!$this->alternativeExists()) {
+            $this->AltBody = 'To view this email message, open it in a program that understands HTML!' .
+                self::CRLF . self::CRLF;
+        }
         return $this->Body;
     }
@@ -2817 +3458 @@
     /**
      * Convert an HTML string into plain text.
+     * This is used by msgHTML().
+     * Note - older versions of this function used a bundled advanced converter
+     * which was been removed for license reasons in #232.
+     * Example usage:
+     * <code>
+     * // Use default conversion
+     * $plain = $mail->html2text($html);
+     * // Use your own custom converter
+     * $plain = $mail->html2text($html, function($html) {
+     *     $converter = new MyHtml2text($html);
+     *     return $converter->get_text();
+     * });
+     * </code>
      * @param string $html The HTML text to convert
-     * @param bool $advanced Should this use the more complex html2text converter or just a simple one?
+     * @param boolean|callable $advanced Any boolean value to use the internal converter,
+     *   or provide your own callable for custom conversion.
      * @return string
      */
     public function html2text($html, $advanced = false)
     {
-        if ($advanced) {
-            require_once 'extras/class.html2text.php';
-            $h = new html2text($html);
-            return $h->get_text();
+        if (is_callable($advanced)) {
+            return call_user_func($advanced, $html);
         }
         return html_entity_decode(
@@ -2845 +3498 @@
     {
         $mimes = array(
-            'xl' => 'application/excel',
-            'hqx' => 'application/mac-binhex40',
-            'cpt' => 'application/mac-compactpro',
-            'bin' => 'application/macbinary',
-            'doc' => 'application/msword',
-            'word' => 'application/msword',
+            'xl'    => 'application/excel',
+            'js'    => 'application/javascript',
+            'hqx'   => 'application/mac-binhex40',
+            'cpt'   => 'application/mac-compactpro',
+            'bin'   => 'application/macbinary',
+            'doc'   => 'application/msword',
+            'word'  => 'application/msword',
+            'xlsx'  => 'application/vnd.openxmlformats-officedocument.spreadsheetml.sheet',
+            'xltx'  => 'application/vnd.openxmlformats-officedocument.spreadsheetml.template',
+            'potx'  => 'application/vnd.openxmlformats-officedocument.presentationml.template',
+            'ppsx'  => 'application/vnd.openxmlformats-officedocument.presentationml.slideshow',
+            'pptx'  => 'application/vnd.openxmlformats-officedocument.presentationml.presentation',
+            'sldx'  => 'application/vnd.openxmlformats-officedocument.presentationml.slide',
+            'docx'  => 'application/vnd.openxmlformats-officedocument.wordprocessingml.document',
+            'dotx'  => 'application/vnd.openxmlformats-officedocument.wordprocessingml.template',
+            'xlam'  => 'application/vnd.ms-excel.addin.macroEnabled.12',
+            'xlsb'  => 'application/vnd.ms-excel.sheet.binary.macroEnabled.12',
             'class' => 'application/octet-stream',
-            'dll' => 'application/octet-stream',
-            'dms' => 'application/octet-stream',
-            'exe' => 'application/octet-stream',
-            'lha' => 'application/octet-stream',
-            'lzh' => 'application/octet-stream',
-            'psd' => 'application/octet-stream',
-            'sea' => 'application/octet-stream',
-            'so' => 'application/octet-stream',
-            'oda' => 'application/oda',
-            'pdf' => 'application/pdf',
-            'ai' => 'application/postscript',
-            'eps' => 'application/postscript',
-            'ps' => 'application/postscript',
-            'smi' => 'application/smil',
-            'smil' => 'application/smil',
-            'mif' => 'application/vnd.mif',
-            'xls' => 'application/vnd.ms-excel',
-            'ppt' => 'application/vnd.ms-powerpoint',
+            'dll'   => 'application/octet-stream',
+            'dms'   => 'application/octet-stream',
+            'exe'   => 'application/octet-stream',
+            'lha'   => 'application/octet-stream',
+            'lzh'   => 'application/octet-stream',
+            'psd'   => 'application/octet-stream',
+            'sea'   => 'application/octet-stream',
+            'so'    => 'application/octet-stream',
+            'oda'   => 'application/oda',
+            'pdf'   => 'application/pdf',
+            'ai'    => 'application/postscript',
+            'eps'   => 'application/postscript',
+            'ps'    => 'application/postscript',
+            'smi'   => 'application/smil',
+            'smil'  => 'application/smil',
+            'mif'   => 'application/vnd.mif',
+            'xls'   => 'application/vnd.ms-excel',
+            'ppt'   => 'application/vnd.ms-powerpoint',
             'wbxml' => 'application/vnd.wap.wbxml',
-            'wmlc' => 'application/vnd.wap.wmlc',
-            'dcr' => 'application/x-director',
-            'dir' => 'application/x-director',
-            'dxr' => 'application/x-director',
-            'dvi' => 'application/x-dvi',
-            'gtar' => 'application/x-gtar',
-            'php3' => 'application/x-httpd-php',
-            'php4' => 'application/x-httpd-php',
-            'php' => 'application/x-httpd-php',
+            'wmlc'  => 'application/vnd.wap.wmlc',
+            'dcr'   => 'application/x-director',
+            'dir'   => 'application/x-director',
+            'dxr'   => 'application/x-director',
+            'dvi'   => 'application/x-dvi',
+            'gtar'  => 'application/x-gtar',
+            'php3'  => 'application/x-httpd-php',
+            'php4'  => 'application/x-httpd-php',
+            'php'   => 'application/x-httpd-php',
             'phtml' => 'application/x-httpd-php',
-            'phps' => 'application/x-httpd-php-source',
-            'js' => 'application/x-javascript',
-            'swf' => 'application/x-shockwave-flash',
-            'sit' => 'application/x-stuffit',
-            'tar' => 'application/x-tar',
-            'tgz' => 'application/x-tar',
-            'xht' => 'application/xhtml+xml',
+            'phps'  => 'application/x-httpd-php-source',
+            'swf'   => 'application/x-shockwave-flash',
+            'sit'   => 'application/x-stuffit',
+            'tar'   => 'application/x-tar',
+            'tgz'   => 'application/x-tar',
+            'xht'   => 'application/xhtml+xml',
             'xhtml' => 'application/xhtml+xml',
-            'zip' => 'application/zip',
-            'mid' => 'audio/midi',
-            'midi' => 'audio/midi',
-            'mp2' => 'audio/mpeg',
-            'mp3' => 'audio/mpeg',
-            'mpga' => 'audio/mpeg',
-            'aif' => 'audio/x-aiff',
-            'aifc' => 'audio/x-aiff',
-            'aiff' => 'audio/x-aiff',
-            'ram' => 'audio/x-pn-realaudio',
-            'rm' => 'audio/x-pn-realaudio',
-            'rpm' => 'audio/x-pn-realaudio-plugin',
-            'ra' => 'audio/x-realaudio',
-            'wav' => 'audio/x-wav',
-            'bmp' => 'image/bmp',
-            'gif' => 'image/gif',
-            'jpeg' => 'image/jpeg',
-            'jpe' => 'image/jpeg',
-            'jpg' => 'image/jpeg',
-            'png' => 'image/png',
-            'tiff' => 'image/tiff',
-            'tif' => 'image/tiff',
-            'eml' => 'message/rfc822',
-            'css' => 'text/css',
-            'html' => 'text/html',
-            'htm' => 'text/html',
+            'zip'   => 'application/zip',
+            'mid'   => 'audio/midi',
+            'midi'  => 'audio/midi',
+            'mp2'   => 'audio/mpeg',
+            'mp3'   => 'audio/mpeg',
+            'mpga'  => 'audio/mpeg',
+            'aif'   => 'audio/x-aiff',
+            'aifc'  => 'audio/x-aiff',
+            'aiff'  => 'audio/x-aiff',
+            'ram'   => 'audio/x-pn-realaudio',
+            'rm'    => 'audio/x-pn-realaudio',
+            'rpm'   => 'audio/x-pn-realaudio-plugin',
+            'ra'    => 'audio/x-realaudio',
+            'wav'   => 'audio/x-wav',
+            'bmp'   => 'image/bmp',
+            'gif'   => 'image/gif',
+            'jpeg'  => 'image/jpeg',
+            'jpe'   => 'image/jpeg',
+            'jpg'   => 'image/jpeg',
+            'png'   => 'image/png',
+            'tiff'  => 'image/tiff',
+            'tif'   => 'image/tiff',
+            'eml'   => 'message/rfc822',
+            'css'   => 'text/css',
+            'html'  => 'text/html',
+            'htm'   => 'text/html',
             'shtml' => 'text/html',
-            'log' => 'text/plain',
-            'text' => 'text/plain',
-            'txt' => 'text/plain',
-            'rtx' => 'text/richtext',
-            'rtf' => 'text/rtf',
-            'xml' => 'text/xml',
-            'xsl' => 'text/xml',
-            'mpeg' => 'video/mpeg',
-            'mpe' => 'video/mpeg',
-            'mpg' => 'video/mpeg',
-            'mov' => 'video/quicktime',
-            'qt' => 'video/quicktime',
-            'rv' => 'video/vnd.rn-realvideo',
-            'avi' => 'video/x-msvideo',
+            'log'   => 'text/plain',
+            'text'  => 'text/plain',
+            'txt'   => 'text/plain',
+            'rtx'   => 'text/richtext',
+            'rtf'   => 'text/rtf',
+            'vcf'   => 'text/vcard',
+            'vcard' => 'text/vcard',
+            'xml'   => 'text/xml',
+            'xsl'   => 'text/xml',
+            'mpeg'  => 'video/mpeg',
+            'mpe'   => 'video/mpeg',
+            'mpg'   => 'video/mpeg',
+            'mov'   => 'video/quicktime',
+            'qt'    => 'video/quicktime',
+            'rv'    => 'video/vnd.rn-realvideo',
+            'avi'   => 'video/x-msvideo',
             'movie' => 'video/x-sgi-movie'
         );
-        return (array_key_exists(strtolower($ext), $mimes) ? $mimes[strtolower($ext)]: 'application/octet-stream');
+        if (array_key_exists(strtolower($ext), $mimes)) {
+            return $mimes[strtolower($ext)];
+        }
+        return 'application/octet-stream';
     }
 
@@ -2944 +3612 @@
     public static function filenameToType($filename)
     {
-        //In case the path is a URL, strip any query string before getting extension
+        // In case the path is a URL, strip any query string before getting extension
         $qpos = strpos($filename, '?');
-        if ($qpos !== false) {
+        if (false !== $qpos) {
             $filename = substr($filename, 0, $qpos);
         }
@@ -2967 +3635 @@
     {
         $ret = array('dirname' => '', 'basename' => '', 'extension' => '', 'filename' => '');
-        $m = array();
-        preg_match('%^(.*?)[\\\\/]*(([^/\\\\]*?)(\.([^\.\\\\/]+?)|))[\\\\/\.]*$%im', $path, $m);
-        if (array_key_exists(1, $m)) {
-            $ret['dirname'] = $m[1];
-        }
-        if (array_key_exists(2, $m)) {
-            $ret['basename'] = $m[2];
-        }
-        if (array_key_exists(5, $m)) {
-            $ret['extension'] = $m[5];
-        }
-        if (array_key_exists(3, $m)) {
-            $ret['filename'] = $m[3];
+        $pathinfo = array();
+        if (preg_match('%^(.*?)[\\\\/]*(([^/\\\\]*?)(\.([^\.\\\\/]+?)|))[\\\\/\.]*$%im', $path, $pathinfo)) {
+            if (array_key_exists(1, $pathinfo)) {
+                $ret['dirname'] = $pathinfo[1];
+            }
+            if (array_key_exists(2, $pathinfo)) {
+                $ret['basename'] = $pathinfo[2];
+            }
+            if (array_key_exists(5, $pathinfo)) {
+                $ret['extension'] = $pathinfo[5];
+            }
+            if (array_key_exists(3, $pathinfo)) {
+                $ret['filename'] = $pathinfo[3];
+            }
         }
         switch ($options) {
@@ -2985 +3654 @@
             case 'dirname':
                 return $ret['dirname'];
-                break;
             case PATHINFO_BASENAME:
             case 'basename':
                 return $ret['basename'];
-                break;
             case PATHINFO_EXTENSION:
             case 'extension':
                 return $ret['extension'];
-                break;
             case PATHINFO_FILENAME:
             case 'filename':
                 return $ret['filename'];
-                break;
             default:
                 return $ret;
@@ -3005 +3670 @@
     /**
      * Set or reset instance properties.
-     *
+     * You should avoid this function - it's more verbose, less efficient, more error-prone and
+     * harder to debug than setting properties directly.
      * Usage Example:
-     * $page->set('X-Priority', '3');
-     *
-     * @access public
-     * @param string $name
-     * @param mixed $value
-     * NOTE: will not work with arrays, there are no arrays to set/reset
-     * @throws phpmailerException
-     * @return bool
-     * @todo Should this not be using __set() magic function?
+     * `$mail->set('SMTPSecure', 'tls');`
+     *   is the same as:
+     * `$mail->SMTPSecure = 'tls';`
+     * @access public
+     * @param string $name The property name to set
+     * @param mixed $value The value to set the property to
+     * @return boolean
+     * @TODO Should this not be using the __set() magic function?
      */
     public function set($name, $value = '')
     {
-        try {
-            if (isset($this->$name)) {
-                $this->$name = $value;
-            } else {
-                throw new phpmailerException($this->lang('variable_set') . $name, self::STOP_CRITICAL);
-            }
-        } catch (Exception $e) {
-            $this->setError($e->getMessage());
-            if ($e->getCode() == self::STOP_CRITICAL) {
-                return false;
-            }
-        }
-        return true;
+        if (property_exists($this, $name)) {
+            $this->$name = $value;
+            return true;
+        } else {
+            $this->setError($this->lang('variable_set') . $name);
+            return false;
+        }
     }
 
@@ -3060 +3719 @@
     }
 
-
-    /**
-     * Set the private key file and password for S/MIME signing.
+    /**
+     * Set the public and private key files and password for S/MIME signing.
      * @access public
      * @param string $cert_filename
      * @param string $key_filename
      * @param string $key_pass Password for private key
-     */
-    public function sign($cert_filename, $key_filename, $key_pass)
+     * @param string $extracerts_filename Optional path to chain certificate
+     */
+    public function sign($cert_filename, $key_filename, $key_pass, $extracerts_filename = '')
     {
         $this->sign_cert_file = $cert_filename;
         $this->sign_key_file = $key_filename;
         $this->sign_key_pass = $key_pass;
+        $this->sign_extracerts_file = $extracerts_filename;
     }
 
@@ -3089 +3749 @@
                 $line .= $txt[$i];
             } else {
-                $line .= "=" . sprintf("%02X", $ord);
+                $line .= '=' . sprintf('%02X', $ord);
             }
         }
@@ -3098 +3758 @@
      * Generate a DKIM signature.
      * @access public
-     * @param string $s Header
+     * @param string $signHeader
      * @throws phpmailerException
-     * @return string
-     */
-    public function DKIM_Sign($s)
+     * @return string The DKIM signature value
+     */
+    public function DKIM_Sign($signHeader)
     {
         if (!defined('PKCS7_TEXT')) {
             if ($this->exceptions) {
-                throw new phpmailerException($this->lang("signing") . ' OpenSSL extension missing.');
+                throw new phpmailerException($this->lang('extension_missing') . 'openssl');
             }
             return '';
         }
-        $privKeyStr = file_get_contents($this->DKIM_private);
-        if ($this->DKIM_passphrase != '') {
+        $privKeyStr = !empty($this->DKIM_private_string) ? $this->DKIM_private_string : file_get_contents($this->DKIM_private);
+        if ('' != $this->DKIM_passphrase) {
             $privKey = openssl_pkey_get_private($privKeyStr, $this->DKIM_passphrase);
         } else {
-            $privKey = $privKeyStr;
-        }
-        if (openssl_sign($s, $signature, $privKey)) {
-            return base64_encode($signature);
-        }
+            $privKey = openssl_pkey_get_private($privKeyStr);
+        }
+        //Workaround for missing digest algorithms in old PHP & OpenSSL versions
+        //@link http://stackoverflow.com/a/11117338/333340
+        if (version_compare(PHP_VERSION, '5.3.0') >= 0 and
+            in_array('sha256WithRSAEncryption', openssl_get_md_methods(true))) {
+            if (openssl_sign($signHeader, $signature, $privKey, 'sha256WithRSAEncryption')) {
+                openssl_pkey_free($privKey);
+                return base64_encode($signature);
+            }
+        } else {
+            $pinfo = openssl_pkey_get_details($privKey);
+            $hash = hash('sha256', $signHeader);
+            //'Magic' constant for SHA256 from RFC3447
+            //@link https://tools.ietf.org/html/rfc3447#page-43
+            $t = '3031300d060960864801650304020105000420' . $hash;
+            $pslen = $pinfo['bits'] / 8 - (strlen($t) / 2 + 3);
+            $eb = pack('H*', '0001' . str_repeat('FF', $pslen) . '00' . $t);
+
+            if (openssl_private_encrypt($eb, $signature, $privKey, OPENSSL_NO_PADDING)) {
+                openssl_pkey_free($privKey);
+                return base64_encode($signature);
+            }
+        }
+        openssl_pkey_free($privKey);
         return '';
     }
@@ -3125 +3805 @@
      * Generate a DKIM canonicalization header.
      * @access public
-     * @param string $s Header
+     * @param string $signHeader Header
      * @return string
      */
-    public function DKIM_HeaderC($s)
-    {
-        $s = preg_replace("/\r\n\s+/", " ", $s);
-        $lines = explode("\r\n", $s);
+    public function DKIM_HeaderC($signHeader)
+    {
+        $signHeader = preg_replace('/\r\n\s+/', ' ', $signHeader);
+        $lines = explode("\r\n", $signHeader);
         foreach ($lines as $key => $line) {
-            list($heading, $value) = explode(":", $line, 2);
+            list($heading, $value) = explode(':', $line, 2);
             $heading = strtolower($heading);
-            $value = preg_replace("/\s+/", " ", $value); // Compress useless spaces
-            $lines[$key] = $heading . ":" . trim($value); // Don't forget to remove WSP around the value
-        }
-        $s = implode("\r\n", $lines);
-        return $s;
+            $value = preg_replace('/\s{2,}/', ' ', $value); // Compress useless spaces
+            $lines[$key] = $heading . ':' . trim($value); // Don't forget to remove WSP around the value
+        }
+        $signHeader = implode("\r\n", $lines);
+        return $signHeader;
     }
 
@@ -3173 +3853 @@
     public function DKIM_Add($headers_line, $subject, $body)
     {
-        $DKIMsignatureType = 'rsa-sha1'; // Signature & hash algorithms
+        $DKIMsignatureType = 'rsa-sha256'; // Signature & hash algorithms
         $DKIMcanonicalization = 'relaxed/simple'; // Canonicalization of header/body
         $DKIMquery = 'dns/txt'; // Query method
@@ -3181 +3861 @@
         $from_header = '';
         $to_header = '';
+        $date_header = '';
         $current = '';
         foreach ($headers as $header) {
@@ -3189 +3870 @@
                 $to_header = $header;
                 $current = 'to_header';
+            } elseif (strpos($header, 'Date:') === 0) {
+                $date_header = $header;
+                $current = 'date_header';
             } else {
-                if ($current && strpos($header, ' =?') === 0) {
-                    $current .= $header;
+                if (!empty($$current) && strpos($header, ' =?') === 0) {
+                    $$current .= $header;
                 } else {
                     $current = '';
@@ -3199 +3883 @@
         $from = str_replace('|', '=7C', $this->DKIM_QP($from_header));
         $to = str_replace('|', '=7C', $this->DKIM_QP($to_header));
+        $date = str_replace('|', '=7C', $this->DKIM_QP($date_header));
         $subject = str_replace(
             '|',
@@ -3206 +3891 @@
         $body = $this->DKIM_BodyC($body);
         $DKIMlen = strlen($body); // Length of body
-        $DKIMb64 = base64_encode(pack("H*", sha1($body))); // Base64 of packed binary SHA-1 hash of body
-        $ident = ($this->DKIM_identity == '') ? '' : " i=" . $this->DKIM_identity . ";";
-        $dkimhdrs = "DKIM-Signature: v=1; a=" .
-            $DKIMsignatureType . "; q=" .
-            $DKIMquery . "; l=" .
-            $DKIMlen . "; s=" .
+        $DKIMb64 = base64_encode(pack('H*', hash('sha256', $body))); // Base64 of packed binary SHA-256 hash of body
+        if ('' == $this->DKIM_identity) {
+            $ident = '';
+        } else {
+            $ident = ' i=' . $this->DKIM_identity . ';';
+        }
+        $dkimhdrs = 'DKIM-Signature: v=1; a=' .
+            $DKIMsignatureType . '; q=' .
+            $DKIMquery . '; l=' .
+            $DKIMlen . '; s=' .
             $this->DKIM_selector .
             ";\r\n" .
-            "\tt=" . $DKIMtime . "; c=" . $DKIMcanonicalization . ";\r\n" .
-            "\th=From:To:Subject;\r\n" .
-            "\td=" . $this->DKIM_domain . ";" . $ident . "\r\n" .
+            "\tt=" . $DKIMtime . '; c=' . $DKIMcanonicalization . ";\r\n" .
+            "\th=From:To:Date:Subject;\r\n" .
+            "\td=" . $this->DKIM_domain . ';' . $ident . "\r\n" .
             "\tz=$from\r\n" .
             "\t|$to\r\n" .
+            "\t|$date\r\n" .
             "\t|$subject;\r\n" .
             "\tbh=" . $DKIMb64 . ";\r\n" .
             "\tb=";
         $toSign = $this->DKIM_HeaderC(
-            $from_header . "\r\n" . $to_header . "\r\n" . $subject_header . "\r\n" . $dkimhdrs
+            $from_header . "\r\n" .
+            $to_header . "\r\n" .
+            $date_header . "\r\n" .
+            $subject_header . "\r\n" .
+            $dkimhdrs
         );
         $signed = $this->DKIM_Sign($toSign);
@@ -3230 +3924 @@
 
     /**
+     * Detect if a string contains a line longer than the maximum line length allowed.
+     * @param string $str
+     * @return boolean
+     * @static
+     */
+    public static function hasLineLongerThanMax($str)
+    {
+        //+2 to include CRLF line break for a 1000 total
+        return (boolean)preg_match('/^(.{'.(self::MAX_LINE_LENGTH + 2).',})/m', $str);
+    }
+
+    /**
+     * Allows for public read access to 'to' property.
+     * @note: Before the send() call, queued addresses (i.e. with IDN) are not yet included.
+     * @access public
+     * @return array
+     */
+    public function getToAddresses()
+    {
+        return $this->to;
+    }
+
+    /**
+     * Allows for public read access to 'cc' property.
+     * @note: Before the send() call, queued addresses (i.e. with IDN) are not yet included.
+     * @access public
+     * @return array
+     */
+    public function getCcAddresses()
+    {
+        return $this->cc;
+    }
+
+    /**
+     * Allows for public read access to 'bcc' property.
+     * @note: Before the send() call, queued addresses (i.e. with IDN) are not yet included.
+     * @access public
+     * @return array
+     */
+    public function getBccAddresses()
+    {
+        return $this->bcc;
+    }
+
+    /**
+     * Allows for public read access to 'ReplyTo' property.
+     * @note: Before the send() call, queued addresses (i.e. with IDN) are not yet included.
+     * @access public
+     * @return array
+     */
+    public function getReplyToAddresses()
+    {
+        return $this->ReplyTo;
+    }
+
+    /**
+     * Allows for public read access to 'all_recipients' property.
+     * @note: Before the send() call, queued addresses (i.e. with IDN) are not yet included.
+     * @access public
+     * @return array
+     */
+    public function getAllRecipientAddresses()
+    {
+        return $this->all_recipients;
+    }
+
+    /**
      * Perform a callback.
-     * @param bool $isSent
-     * @param string $to
-     * @param string $cc
-     * @param string $bcc
+     * @param boolean $isSent
+     * @param array $to
+     * @param array $cc
+     * @param array $bcc
      * @param string $subject
      * @param string $body
      * @param string $from
      */
-    protected function doCallback($isSent, $to, $cc, $bcc, $subject, $body, $from = null)
+    protected function doCallback($isSent, $to, $cc, $bcc, $subject, $body, $from)
     {
         if (!empty($this->action_function) && is_callable($this->action_function)) {

branches/4.1/src/wp-includes/class-smtp.php

@@ -2 +2 @@
 /**
  * PHPMailer RFC821 SMTP email transport class.
- * Version 5.2.7
- * PHP version 5.0.0
- * @category  PHP
- * @package   PHPMailer
- * @link      https://github.com/PHPMailer/PHPMailer/
- * @author Marcus Bointon (coolbru) <phpmailer@synchromedia.co.uk>
+ * PHP Version 5
+ * @package PHPMailer
+ * @link https://github.com/PHPMailer/PHPMailer/ The PHPMailer GitHub project
+ * @author Marcus Bointon (Synchro/coolbru) <phpmailer@synchromedia.co.uk>
  * @author Jim Jagielski (jimjag) <jimjag@gmail.com>
  * @author Andy Prevost (codeworxtech) <codeworxtech@users.sourceforge.net>
- * @copyright 2013 Marcus Bointon
- * @copyright 2004 - 2008 Andy Prevost
+ * @author Brent R. Matzelle (original founder)
+ * @copyright 2014 Marcus Bointon
  * @copyright 2010 - 2012 Jim Jagielski
- * @license   http://www.gnu.org/copyleft/lesser.html Distributed under the Lesser General Public License (LGPL)
+ * @copyright 2004 - 2009 Andy Prevost
+ * @license http://www.gnu.org/copyleft/lesser.html GNU Lesser General Public License
+ * @note This program is distributed in the hope that it will be useful - WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.
  */
 
 /**
  * PHPMailer RFC821 SMTP email transport class.
- *
- * Implements RFC 821 SMTP commands
- * and provides some utility methods for sending mail to an SMTP server.
- *
- * PHP Version 5.0.0
- *
- * @category PHP
- * @package  PHPMailer
- * @link     https://github.com/PHPMailer/PHPMailer/blob/master/class.smtp.php
- * @author   Chris Ryan <unknown@example.com>
- * @author   Marcus Bointon <phpmailer@synchromedia.co.uk>
- * @license  http://www.gnu.org/copyleft/lesser.html Distributed under the Lesser General Public License (LGPL)
+ * Implements RFC 821 SMTP commands and provides some utility methods for sending mail to an SMTP server.
+ * @package PHPMailer
+ * @author Chris Ryan
+ * @author Marcus Bointon <phpmailer@synchromedia.co.uk>
  */
-
 class SMTP
 {
     /**
+     * The PHPMailer SMTP version number.
+     * @var string
+     */
+    const VERSION = '5.2.21';
+
+    /**
+     * SMTP line break constant.
+     * @var string
+     */
+    const CRLF = "\r\n";
+
+    /**
+     * The SMTP port to use if one is not specified.
+     * @var integer
+     */
+    const DEFAULT_SMTP_PORT = 25;
+
+    /**
+     * The maximum line length allowed by RFC 2822 section 2.1.1
+     * @var integer
+     */
+    const MAX_LINE_LENGTH = 998;
+
+    /**
+     * Debug level for no output
+     */
+    const DEBUG_OFF = 0;
+
+    /**
+     * Debug level to show client -> server messages
+     */
+    const DEBUG_CLIENT = 1;
+
+    /**
+     * Debug level to show client -> server and server -> client messages
+     */
+    const DEBUG_SERVER = 2;
+
+    /**
+     * Debug level to show connection status, client -> server and server -> client messages
+     */
+    const DEBUG_CONNECTION = 3;
+
+    /**
+     * Debug level to show all messages
+     */
+    const DEBUG_LOWLEVEL = 4;
+
+    /**
      * The PHPMailer SMTP Version number.
-     */
-    const VERSION = '5.2.7';
-
-    /**
-     * SMTP line break constant.
-     */
-    const CRLF = "\r\n";
-
-    /**
-     * The SMTP port to use if one is not specified.
-     */
-    const DEFAULT_SMTP_PORT = 25;
-
-    /**
-     * The PHPMailer SMTP Version number.
-     * @type string
-     * @deprecated This should be a constant
+     * @var string
+     * @deprecated Use the `VERSION` constant instead
      * @see SMTP::VERSION
      */
-    public $Version = '5.2.7';
+    public $Version = '5.2.21';
 
     /**
      * SMTP server port number.
-     * @type int
-     * @deprecated This is only ever ued as default value, so should be a constant
+     * @var integer
+     * @deprecated This is only ever used as a default value, so use the `DEFAULT_SMTP_PORT` constant instead
      * @see SMTP::DEFAULT_SMTP_PORT
      */
@@ -66 +93 @@
 
     /**
-     * SMTP reply line ending
-     * @type string
-     * @deprecated Use the class constant instead
+     * SMTP reply line ending.
+     * @var string
+     * @deprecated Use the `CRLF` constant instead
      * @see SMTP::CRLF
      */
@@ -75 +102 @@
     /**
      * Debug output level.
-     * Options: 0 for no output, 1 for commands, 2 for data and commands
-     * @type int
-     */
-    public $do_debug = 0;
-
-    /**
-     * The function/method to use for debugging output.
-     * Options: 'echo', 'html' or 'error_log'
-     * @type string
+     * Options:
+     * * self::DEBUG_OFF (`0`) No debug output, default
+     * * self::DEBUG_CLIENT (`1`) Client commands
+     * * self::DEBUG_SERVER (`2`) Client commands and server responses
+     * * self::DEBUG_CONNECTION (`3`) As DEBUG_SERVER plus connection status
+     * * self::DEBUG_LOWLEVEL (`4`) Low-level data output, all messages
+     * @var integer
+     */
+    public $do_debug = self::DEBUG_OFF;
+
+    /**
+     * How to handle debug output.
+     * Options:
+     * * `echo` Output plain-text as-is, appropriate for CLI
+     * * `html` Output escaped, line breaks converted to `<br>`, appropriate for browser output
+     * * `error_log` Output to error log as configured in php.ini
+     *
+     * Alternatively, you can provide a callable expecting two params: a message string and the debug level:
+     * <code>
+     * $smtp->Debugoutput = function($str, $level) {echo "debug level $level; message: $str";};
+     * </code>
+     * @var string|callable
      */
     public $Debugoutput = 'echo';
@@ -89 +129 @@
     /**
      * Whether to use VERP.
-     * @type bool
+     * @link http://en.wikipedia.org/wiki/Variable_envelope_return_path
+     * @link http://www.postfix.org/VERP_README.html Info on VERP
+     * @var boolean
      */
     public $do_verp = false;
 
     /**
-     * The SMTP timeout value for reads, in seconds.
-     * @type int
-     */
-    public $Timeout = 15;
-
-    /**
-     * The SMTP timelimit value for reads, in seconds.
-     * @type int
-     */
-    public $Timelimit = 30;
+     * The timeout value for connection, in seconds.
+     * Default of 5 minutes (300sec) is from RFC2821 section 4.5.3.2
+     * This needs to be quite high to function correctly with hosts using greetdelay as an anti-spam measure.
+     * @link http://tools.ietf.org/html/rfc2821#section-4.5.3.2
+     * @var integer
+     */
+    public $Timeout = 300;
+
+    /**
+     * How long to wait for commands to complete, in seconds.
+     * Default of 5 minutes (300sec) is from RFC2821 section 4.5.3.2
+     * @var integer
+     */
+    public $Timelimit = 300;
+
+    /**
+     * @var array patterns to extract smtp transaction id from smtp reply
+     * Only first capture group will be use, use non-capturing group to deal with it
+     * Extend this class to override this property to fulfil your needs.
+     */
+    protected $smtp_transaction_id_patterns = array(
+        'exim' => '/[0-9]{3} OK id=(.*)/',
+        'sendmail' => '/[0-9]{3} 2.0.0 (.*) Message/',
+        'postfix' => '/[0-9]{3} 2.0.0 Ok: queued as (.*)/'
+    );
 
     /**
      * The socket for the server connection.
-     * @type resource
+     * @var resource
      */
     protected $smtp_conn;
 
     /**
-     * Error message, if any, for the last call.
-     * @type string
-     */
-    protected $error = '';
+     * Error information, if any, for the last SMTP command.
+     * @var array
+     */
+    protected $error = array(
+        'error' => '',
+        'detail' => '',
+        'smtp_code' => '',
+        'smtp_code_ex' => ''
+    );
 
     /**
      * The reply the server sent to us for HELO.
-     * @type string
-     */
-    protected $helo_rply = '';
+     * If null, no HELO string has yet been received.
+     * @var string|null
+     */
+    protected $helo_rply = null;
+
+    /**
+     * The set of SMTP extensions sent in reply to EHLO command.
+     * Indexes of the array are extension names.
+     * Value at index 'HELO' or 'EHLO' (according to command that was sent)
+     * represents the server name. In case of HELO it is the only element of the array.
+     * Other values can be boolean TRUE or an array containing extension options.
+     * If null, no HELO/EHLO string has yet been received.
+     * @var array|null
+     */
+    protected $server_caps = null;
 
     /**
      * The most recent reply received from the server.
-     * @type string
+     * @var string
      */
     protected $last_reply = '';
 
     /**
-     * Constructor.
-     * @access public
-     */
-    public function __construct()
-    {
-        $this->smtp_conn = 0;
-        $this->error = null;
-        $this->helo_rply = null;
-
-        $this->do_debug = 0;
-    }
-
-    /**
      * Output debugging info via a user-selected method.
+     * @see SMTP::$Debugoutput
+     * @see SMTP::$do_debug
      * @param string $str Debug string to output
+     * @param integer $level The debug level of this message; see DEBUG_* constants
      * @return void
      */
-    protected function edebug($str)
-    {
+    protected function edebug($str, $level = 0)
+    {
+        if ($level > $this->do_debug) {
+            return;
+        }
+        //Avoid clash with built-in function names
+        if (!in_array($this->Debugoutput, array('error_log', 'html', 'echo')) and is_callable($this->Debugoutput)) {
+            call_user_func($this->Debugoutput, $str, $level);
+            return;
+        }
         switch ($this->Debugoutput) {
             case 'error_log':
@@ -165 +237 @@
             case 'echo':
             default:
-                //Just echoes whatever was received
-                echo $str;
+                //Normalize line breaks
+                $str = preg_replace('/(\r\n|\r|\n)/ms', "\n", $str);
+                echo gmdate('Y-m-d H:i:s') . "\t" . str_replace(
+                    "\n",
+                    "\n                   \t                  ",
+                    trim($str)
+                )."\n";
         }
     }
@@ -172 +249 @@
     /**
      * Connect to an SMTP server.
-     * @param string $host    SMTP server IP or host name
-     * @param int $port    The port number to connect to
-     * @param int $timeout How long to wait for the connection to open
+     * @param string $host SMTP server IP or host name
+     * @param integer $port The port number to connect to
+     * @param integer $timeout How long to wait for the connection to open
      * @param array $options An array of options for stream_context_create()
      * @access public
-     * @return bool
+     * @return boolean
      */
     public function connect($host, $port = null, $timeout = 30, $options = array())
     {
+        static $streamok;
+        //This is enabled by default since 5.0.0 but some providers disable it
+        //Check this once and cache the result
+        if (is_null($streamok)) {
+            $streamok = function_exists('stream_socket_client');
+        }
         // Clear errors to avoid confusion
-        $this->error = null;
-
+        $this->setError('');
         // Make sure we are __not__ connected
         if ($this->connected()) {
             // Already connected, generate error
-            $this->error = array('error' => 'Already connected to a server');
+            $this->setError('Already connected to a server');
             return false;
         }
-
         if (empty($port)) {
             $port = self::DEFAULT_SMTP_PORT;
         }
-
         // Connect to the SMTP server
+        $this->edebug(
+            "Connection: opening to $host:$port, timeout=$timeout, options=".var_export($options, true),
+            self::DEBUG_CONNECTION
+        );
         $errno = 0;
         $errstr = '';
-        $socket_context = stream_context_create($options);
-        //Suppress errors; connection failures are handled at a higher level
-        $this->smtp_conn = @stream_socket_client(
-            $host . ":" . $port,
-            $errno,
-            $errstr,
-            $timeout,
-            STREAM_CLIENT_CONNECT,
-            $socket_context
-        );
-
+        if ($streamok) {
+            $socket_context = stream_context_create($options);
+            set_error_handler(array($this, 'errorHandler'));
+            $this->smtp_conn = stream_socket_client(
+                $host . ":" . $port,
+                $errno,
+                $errstr,
+                $timeout,
+                STREAM_CLIENT_CONNECT,
+                $socket_context
+            );
+            restore_error_handler();
+        } else {
+            //Fall back to fsockopen which should work in more places, but is missing some features
+            $this->edebug(
+                "Connection: stream_socket_client not available, falling back to fsockopen",
+                self::DEBUG_CONNECTION
+            );
+            set_error_handler(array($this, 'errorHandler'));
+            $this->smtp_conn = fsockopen(
+                $host,
+                $port,
+                $errno,
+                $errstr,
+                $timeout
+            );
+            restore_error_handler();
+        }
         // Verify we connected properly
-        if (empty($this->smtp_conn)) {
-            $this->error = array(
-                'error' => 'Failed to connect to server',
-                'errno' => $errno,
-                'errstr' => $errstr
+        if (!is_resource($this->smtp_conn)) {
+            $this->setError(
+                'Failed to connect to server',
+                $errno,
+                $errstr
             );
-            if ($this->do_debug >= 1) {
-                $this->edebug(
-                    'SMTP -> ERROR: ' . $this->error['error']
-                    . ": $errstr ($errno)"
-                );
-            }
+            $this->edebug(
+                'SMTP ERROR: ' . $this->error['error']
+                . ": $errstr ($errno)",
+                self::DEBUG_CLIENT
+            );
             return false;
         }
-
+        $this->edebug('Connection: opened', self::DEBUG_CONNECTION);
         // SMTP server can take longer to respond, give longer timeout for first read
         // Windows does not have support for this timeout function
         if (substr(PHP_OS, 0, 3) != 'WIN') {
             $max = ini_get('max_execution_time');
-            if ($max != 0 && $timeout > $max) { // Don't bother if unlimited
+            // Don't bother if unlimited
+            if ($max != 0 && $timeout > $max) {
                 @set_time_limit($timeout);
             }
             stream_set_timeout($this->smtp_conn, $timeout, 0);
         }
-
         // Get any announcement
         $announce = $this->get_lines();
-
-        if ($this->do_debug >= 2) {
-            $this->edebug('SMTP -> FROM SERVER:' . $announce);
-        }
-
+        $this->edebug('SERVER -> CLIENT: ' . $announce, self::DEBUG_SERVER);
         return true;
     }
@@ -248 +344 @@
      * Initiate a TLS (encrypted) session.
      * @access public
-     * @return bool
+     * @return boolean
      */
     public function startTLS()
     {
-        if (!$this->sendCommand("STARTTLS", "STARTTLS", 220)) {
+        if (!$this->sendCommand('STARTTLS', 'STARTTLS', 220)) {
             return false;
         }
+
+        //Allow the best TLS version(s) we can
+        $crypto_method = STREAM_CRYPTO_METHOD_TLS_CLIENT;
+
+        //PHP 5.6.7 dropped inclusion of TLS 1.1 and 1.2 in STREAM_CRYPTO_METHOD_TLS_CLIENT
+        //so add them back in manually if we can
+        if (defined('STREAM_CRYPTO_METHOD_TLSv1_2_CLIENT')) {
+            $crypto_method |= STREAM_CRYPTO_METHOD_TLSv1_2_CLIENT;
+            $crypto_method |= STREAM_CRYPTO_METHOD_TLSv1_1_CLIENT;
+        }
+
         // Begin encrypted connection
         if (!stream_socket_enable_crypto(
             $this->smtp_conn,
             true,
-            STREAM_CRYPTO_METHOD_TLS_CLIENT
-        )
-        ) {
+            $crypto_method
+        )) {
             return false;
         }
@@ -271 +377 @@
      * Must be run after hello().
      * @see hello()
-     * @param string $username    The user name
-     * @param string $password    The password
-     * @param string $authtype    The auth type (PLAIN, LOGIN, NTLM, CRAM-MD5)
-     * @param string $realm       The auth realm for NTLM
+     * @param string $username The user name
+     * @param string $password The password
+     * @param string $authtype The auth type (PLAIN, LOGIN, CRAM-MD5)
+     * @param string $realm The auth realm for NTLM
      * @param string $workstation The auth workstation for NTLM
-     * @access public
-     * @return bool True if successfully authenticated.
+     * @param null|OAuth $OAuth An optional OAuth instance (@see PHPMailerOAuth)
+     * @return bool True if successfully authenticated.* @access public
      */
     public function authenticate(
         $username,
         $password,
-        $authtype = 'LOGIN',
+        $authtype = null,
         $realm = '',
-        $workstation = ''
+        $workstation = '',
+        $OAuth = null
     ) {
-        if (empty($authtype)) {
+        if (!$this->server_caps) {
+            $this->setError('Authentication is not allowed before HELO/EHLO');
+            return false;
+        }
+
+        if (array_key_exists('EHLO', $this->server_caps)) {
+        // SMTP extensions are available. Let's try to find a proper authentication method
+
+            if (!array_key_exists('AUTH', $this->server_caps)) {
+                $this->setError('Authentication is not allowed at this stage');
+                // 'at this stage' means that auth may be allowed after the stage changes
+                // e.g. after STARTTLS
+                return false;
+            }
+
+            self::edebug('Auth method requested: ' . ($authtype ? $authtype : 'UNKNOWN'), self::DEBUG_LOWLEVEL);
+            self::edebug(
+                'Auth methods available on the server: ' . implode(',', $this->server_caps['AUTH']),
+                self::DEBUG_LOWLEVEL
+            );
+
+            if (empty($authtype)) {
+                foreach (array('CRAM-MD5', 'LOGIN', 'PLAIN') as $method) {
+                    if (in_array($method, $this->server_caps['AUTH'])) {
+                        $authtype = $method;
+                        break;
+                    }
+                }
+                if (empty($authtype)) {
+                    $this->setError('No supported authentication methods found');
+                    return false;
+                }
+                self::edebug('Auth method selected: '.$authtype, self::DEBUG_LOWLEVEL);
+            }
+
+            if (!in_array($authtype, $this->server_caps['AUTH'])) {
+                $this->setError("The requested authentication method \"$authtype\" is not supported by the server");
+                return false;
+            }
+        } elseif (empty($authtype)) {
             $authtype = 'LOGIN';
         }
-
         switch ($authtype) {
             case 'PLAIN':
@@ -318 +463 @@
                 }
                 break;
-            case 'NTLM':
-                /*
-                 * ntlm_sasl_client.php
-                 * Bundled with Permission
-                 *
-                 * How to telnet in windows:
-                 * http://technet.microsoft.com/en-us/library/aa995718%28EXCHG.65%29.aspx
-                 * PROTOCOL Docs http://curl.haxx.se/rfc/ntlm.html#ntlmSmtpAuthentication
-                 */
-                require_once 'extras/ntlm_sasl_client.php';
-                $temp = new stdClass();
-                $ntlm_client = new ntlm_sasl_client_class;
-                //Check that functions are available
-                if (!$ntlm_client->Initialize($temp)) {
-                    $this->error = array('error' => $temp->error);
-                    if ($this->do_debug >= 1) {
-                        $this->edebug(
-                            'You need to enable some modules in your php.ini file: '
-                            . $this->error['error']
-                        );
-                    }
-                    return false;
-                }
-                //msg1
-                $msg1 = $ntlm_client->TypeMsg1($realm, $workstation); //msg1
-
-                if (!$this->sendCommand(
-                    'AUTH NTLM',
-                    'AUTH NTLM ' . base64_encode($msg1),
-                    334
-                )
-                ) {
-                    return false;
-                }
-
-                //Though 0 based, there is a white space after the 3 digit number
-                //msg2
-                $challenge = substr($this->last_reply, 3);
-                $challenge = base64_decode($challenge);
-                $ntlm_res = $ntlm_client->NTLMResponse(
-                    substr($challenge, 24, 8),
-                    $password
-                );
-                //msg3
-                $msg3 = $ntlm_client->TypeMsg3(
-                    $ntlm_res,
-                    $username,
-                    $realm,
-                    $workstation
-                );
-                // send encoded username
-                return $this->sendCommand('Username', base64_encode($msg3), 235);
-                break;
             case 'CRAM-MD5':
                 // Start authentication
@@ -384 +476 @@
                 // send encoded credentials
                 return $this->sendCommand('Username', base64_encode($response), 235);
-                break;
+            default:
+                $this->setError("Authentication method \"$authtype\" is not supported");
+                return false;
         }
         return true;
@@ -412 +506 @@
         // by Lance Rushing
 
-        $b = 64; // byte length for md5
-        if (strlen($key) > $b) {
+        $bytelen = 64; // byte length for md5
+        if (strlen($key) > $bytelen) {
             $key = pack('H*', md5($key));
         }
-        $key = str_pad($key, $b, chr(0x00));
-        $ipad = str_pad('', $b, chr(0x36));
-        $opad = str_pad('', $b, chr(0x5c));
+        $key = str_pad($key, $bytelen, chr(0x00));
+        $ipad = str_pad('', $bytelen, chr(0x36));
+        $opad = str_pad('', $bytelen, chr(0x5c));
         $k_ipad = $key ^ $ipad;
         $k_opad = $key ^ $opad;
@@ -428 +522 @@
      * Check connection state.
      * @access public
-     * @return bool True if connected.
+     * @return boolean True if connected.
      */
     public function connected()
     {
-        if (!empty($this->smtp_conn)) {
+        if (is_resource($this->smtp_conn)) {
             $sock_status = stream_get_meta_data($this->smtp_conn);
             if ($sock_status['eof']) {
-                // the socket is valid but we are not connected
-                if ($this->do_debug >= 1) {
-                    $this->edebug(
-                        'SMTP -> NOTICE: EOF caught while checking if connected'
-                    );
-                }
+                // The socket is valid but we are not connected
+                $this->edebug(
+                    'SMTP NOTICE: EOF caught while checking if connected',
+                    self::DEBUG_CLIENT
+                );
                 $this->close();
                 return false;
@@ -458 +551 @@
     public function close()
     {
-        $this->error = null; // so there is no confusion
+        $this->setError('');
+        $this->server_caps = null;
         $this->helo_rply = null;
-        if (!empty($this->smtp_conn)) {
+        if (is_resource($this->smtp_conn)) {
             // close the connection and cleanup
             fclose($this->smtp_conn);
-            $this->smtp_conn = 0;
+            $this->smtp_conn = null; //Makes for cleaner serialization
+            $this->edebug('Connection: closed', self::DEBUG_CONNECTION);
         }
     }
@@ -477 +572 @@
      * @param string $msg_data Message data to send
      * @access public
-     * @return bool
+     * @return boolean
      */
     public function data($msg_data)
     {
+        //This will use the standard timelimit
         if (!$this->sendCommand('DATA', 'DATA', 354)) {
             return false;
@@ -486 +582 @@
 
         /* The server is ready to accept data!
-         * according to rfc821 we should not send more than 1000
-         * including the CRLF
-         * characters on a single line so we will break the data up
-         * into lines by \r and/or \n then if needed we will break
-         * each of those into smaller lines to fit within the limit.
-         * in addition we will be looking for lines that start with
-         * a period '.' and append and additional period '.' to that
-         * line. NOTE: this does not count towards limit.
+         * According to rfc821 we should not send more than 1000 characters on a single line (including the CRLF)
+         * so we will break the data up into lines by \r and/or \n then if needed we will break each of those into
+         * smaller lines to fit within the limit.
+         * We will also look for lines that start with a '.' and prepend an additional '.'.
+         * NOTE: this does not count towards line-length limit.
          */
 
-        // Normalize the line breaks before exploding
-        $msg_data = str_replace("\r\n", "\n", $msg_data);
-        $msg_data = str_replace("\r", "\n", $msg_data);
-        $lines = explode("\n", $msg_data);
-
-        /* We need to find a good way to determine if headers are
-         * in the msg_data or if it is a straight msg body
-         * currently I am assuming rfc822 definitions of msg headers
-         * and if the first field of the first line (':' separated)
-         * does not contain a space then it _should_ be a header
-         * and we can process all lines before a blank "" line as
-         * headers.
+        // Normalize line breaks before exploding
+        $lines = explode("\n", str_replace(array("\r\n", "\r"), "\n", $msg_data));
+
+        /* To distinguish between a complete RFC822 message and a plain message body, we check if the first field
+         * of the first line (':' separated) does not contain a space then it _should_ be a header and we will
+         * process all lines before a blank line as headers.
          */
 
         $field = substr($lines[0], 0, strpos($lines[0], ':'));
         $in_headers = false;
-        if (!empty($field) && !strstr($field, ' ')) {
+        if (!empty($field) && strpos($field, ' ') === false) {
             $in_headers = true;
         }
 
-        //RFC 2822 section 2.1.1 limit
-        $max_line_length = 998;
-
         foreach ($lines as $line) {
-            $lines_out = null;
-            if ($line == '' && $in_headers) {
+            $lines_out = array();
+            if ($in_headers and $line == '') {
                 $in_headers = false;
             }
-            // ok we need to break this line up into several smaller lines
-            while (strlen($line) > $max_line_length) {
-                $pos = strrpos(substr($line, 0, $max_line_length), ' ');
-
-                // Patch to fix DOS attack
+            //Break this line up into several smaller lines if it's too long
+            //Micro-optimisation: isset($str[$len]) is faster than (strlen($str) > $len),
+            while (isset($line[self::MAX_LINE_LENGTH])) {
+                //Working backwards, try to find a space within the last MAX_LINE_LENGTH chars of the line to break on
+                //so as to avoid breaking in the middle of a word
+                $pos = strrpos(substr($line, 0, self::MAX_LINE_LENGTH), ' ');
+                //Deliberately matches both false and 0
                 if (!$pos) {
-                    $pos = $max_line_length - 1;
+                    //No nice break found, add a hard break
+                    $pos = self::MAX_LINE_LENGTH - 1;
                     $lines_out[] = substr($line, 0, $pos);
                     $line = substr($line, $pos);
                 } else {
+                    //Break at the found point
                     $lines_out[] = substr($line, 0, $pos);
+                    //Move along by the amount we dealt with
                     $line = substr($line, $pos + 1);
                 }
-
-                /* If processing headers add a LWSP-char to the front of new line
-                 * rfc822 on long msg headers
-                 */
+                //If processing headers add a LWSP-char to the front of new line RFC822 section 3.1.1
                 if ($in_headers) {
                     $line = "\t" . $line;
@@ -547 +633 @@
             $lines_out[] = $line;
 
-            // send the lines to the server
-            while (list(, $line_out) = @each($lines_out)) {
-                if (strlen($line_out) > 0) {
-                    if (substr($line_out, 0, 1) == '.') {
-                        $line_out = '.' . $line_out;
-                    }
+            //Send the lines to the server
+            foreach ($lines_out as $line_out) {
+                //RFC2821 section 4.5.2
+                if (!empty($line_out) and $line_out[0] == '.') {
+                    $line_out = '.' . $line_out;
                 }
                 $this->client_send($line_out . self::CRLF);
@@ -558 +643 @@
         }
 
-        // Message data has been sent, complete the command
-        return $this->sendCommand('DATA END', '.', 250);
+        //Message data has been sent, complete the command
+        //Increase timelimit for end of DATA command
+        $savetimelimit = $this->Timelimit;
+        $this->Timelimit = $this->Timelimit * 2;
+        $result = $this->sendCommand('DATA END', '.', 250);
+        //Restore timelimit
+        $this->Timelimit = $savetimelimit;
+        return $result;
     }
 
@@ -566 +657 @@
      * Used to identify the sending server to the receiving server.
      * This makes sure that client and server are in a known state.
-     * Implements from RFC 821: HELO <SP> <domain> <CRLF>
+     * Implements RFC 821: HELO <SP> <domain> <CRLF>
      * and RFC 2821 EHLO.
      * @param string $host The host name or IP to connect to
      * @access public
-     * @return bool
+     * @return boolean
      */
     public function hello($host = '')
     {
-        // Try extended hello first (RFC 2821)
-        if (!$this->sendHello('EHLO', $host)) {
-            if (!$this->sendHello('HELO', $host)) {
-                return false;
-            }
-        }
-
-        return true;
+        //Try extended hello first (RFC 2821)
+        return (boolean)($this->sendHello('EHLO', $host) or $this->sendHello('HELO', $host));
     }
 
@@ -589 +674 @@
      * @see hello()
      * @param string $hello The HELO string
-     * @param string $host  The hostname to say we are
+     * @param string $host The hostname to say we are
      * @access protected
-     * @return bool
+     * @return boolean
      */
     protected function sendHello($hello, $host)
@@ -597 +682 @@
         $noerror = $this->sendCommand($hello, $hello . ' ' . $host, 250);
         $this->helo_rply = $this->last_reply;
+        if ($noerror) {
+            $this->parseHelloFields($hello);
+        } else {
+            $this->server_caps = null;
+        }
         return $noerror;
+    }
+
+    /**
+     * Parse a reply to HELO/EHLO command to discover server extensions.
+     * In case of HELO, the only parameter that can be discovered is a server name.
+     * @access protected
+     * @param string $type - 'HELO' or 'EHLO'
+     */
+    protected function parseHelloFields($type)
+    {
+        $this->server_caps = array();
+        $lines = explode("\n", $this->helo_rply);
+
+        foreach ($lines as $n => $s) {
+            //First 4 chars contain response code followed by - or space
+            $s = trim(substr($s, 4));
+            if (empty($s)) {
+                continue;
+            }
+            $fields = explode(' ', $s);
+            if (!empty($fields)) {
+                if (!$n) {
+                    $name = $type;
+                    $fields = $fields[0];
+                } else {
+                    $name = array_shift($fields);
+                    switch ($name) {
+                        case 'SIZE':
+                            $fields = ($fields ? $fields[0] : 0);
+                            break;
+                        case 'AUTH':
+                            if (!is_array($fields)) {
+                                $fields = array();
+                            }
+                            break;
+                        default:
+                            $fields = true;
+                    }
+                }
+                $this->server_caps[$name] = $fields;
+            }
+        }
     }
 
@@ -609 +741 @@
      * @param string $from Source address of this message
      * @access public
-     * @return bool
+     * @return boolean
      */
     public function mail($from)
@@ -625 +757 @@
      * Closes the socket if there is no error or the $close_on_error argument is true.
      * Implements from rfc 821: QUIT <CRLF>
-     * @param bool $close_on_error Should the connection close if an error occurs?
-     * @access public
-     * @return bool
+     * @param boolean $close_on_error Should the connection close if an error occurs?
+     * @access public
+     * @return boolean
      */
     public function quit($close_on_error = true)
     {
         $noerror = $this->sendCommand('QUIT', 'QUIT', 221);
-        $e = $this->error; //Save any error
+        $err = $this->error; //Save any error
         if ($noerror or $close_on_error) {
             $this->close();
-            $this->error = $e; //Restore any error from the quit command
+            $this->error = $err; //Restore any error from the quit command
         }
         return $noerror;
@@ -642 +774 @@
     /**
      * Send an SMTP RCPT command.
-     * Sets the TO argument to $to.
+     * Sets the TO argument to $toaddr.
      * Returns true if the recipient was accepted false if it was rejected.
      * Implements from rfc 821: RCPT <SP> TO:<forward-path> <CRLF>
-     * @param string $to The address the message is being sent to
-     * @access public
-     * @return bool
-     */
-    public function recipient($to)
+     * @param string $address The address the message is being sent to
+     * @access public
+     * @return boolean
+     */
+    public function recipient($address)
     {
         return $this->sendCommand(
-            'RCPT TO ',
-            'RCPT TO:<' . $to . '>',
+            'RCPT TO',
+            'RCPT TO:<' . $address . '>',
             array(250, 251)
         );
@@ -663 +795 @@
      * Implements rfc 821: RSET <CRLF>
      * @access public
-     * @return bool True on success.
+     * @return boolean True on success.
      */
     public function reset()
@@ -672 +804 @@
     /**
      * Send a command to an SMTP server and check its return code.
-     * @param string $command       The command name - not sent to the server
+     * @param string $command The command name - not sent to the server
      * @param string $commandstring The actual command to send
-     * @param int|array $expect     One or more expected integer success codes
+     * @param integer|array $expect One or more expected integer success codes
      * @access protected
-     * @return bool True on success.
+     * @return boolean True on success.
      */
     protected function sendCommand($command, $commandstring, $expect)
     {
         if (!$this->connected()) {
-            $this->error = array(
-                "error" => "Called $command without being connected"
+            $this->setError("Called $command without being connected");
+            return false;
+        }
+        //Reject line breaks in all commands
+        if (strpos($commandstring, "\n") !== false or strpos($commandstring, "\r") !== false) {
+            $this->setError("Command '$command' contained line breaks");
+            return false;
+        }
+        $this->client_send($commandstring . self::CRLF);
+
+        $this->last_reply = $this->get_lines();
+        // Fetch SMTP code and possible error code explanation
+        $matches = array();
+        if (preg_match("/^([0-9]{3})[ -](?:([0-9]\\.[0-9]\\.[0-9]) )?/", $this->last_reply, $matches)) {
+            $code = $matches[1];
+            $code_ex = (count($matches) > 2 ? $matches[2] : null);
+            // Cut off error code from each response line
+            $detail = preg_replace(
+                "/{$code}[ -]".($code_ex ? str_replace('.', '\\.', $code_ex).' ' : '')."/m",
+                '',
+                $this->last_reply
+            );
+        } else {
+            // Fall back to simple parsing if regex fails
+            $code = substr($this->last_reply, 0, 3);
+            $code_ex = null;
+            $detail = substr($this->last_reply, 4);
+        }
+
+        $this->edebug('SERVER -> CLIENT: ' . $this->last_reply, self::DEBUG_SERVER);
+
+        if (!in_array($code, (array)$expect)) {
+            $this->setError(
+                "$command command failed",
+                $detail,
+                $code,
+                $code_ex
+            );
+            $this->edebug(
+                'SMTP ERROR: ' . $this->error['error'] . ': ' . $this->last_reply,
+                self::DEBUG_CLIENT
             );
             return false;
         }
-        $this->client_send($commandstring . self::CRLF);
-
-        $reply = $this->get_lines();
-        $code = substr($reply, 0, 3);
-
-        if ($this->do_debug >= 2) {
-            $this->edebug('SMTP -> FROM SERVER:' . $reply);
-        }
-
-        if (!in_array($code, (array)$expect)) {
-            $this->last_reply = null;
-            $this->error = array(
-                "error" => "$command command failed",
-                "smtp_code" => $code,
-                "detail" => substr($reply, 4)
-            );
-            if ($this->do_debug >= 1) {
-                $this->edebug(
-                    'SMTP -> ERROR: ' . $this->error['error'] . ': ' . $reply
-                );
-            }
-            return false;
-        }
-
-        $this->last_reply = $reply;
-        $this->error = null;
+
+        $this->setError('');
         return true;
     }
@@ -726 +873 @@
      * @param string $from The address the message is from
      * @access public
-     * @return bool
+     * @return boolean
      */
     public function sendAndMail($from)
     {
-        return $this->sendCommand("SAML", "SAML FROM:$from", 250);
+        return $this->sendCommand('SAML', "SAML FROM:$from", 250);
     }
 
@@ -737 +884 @@
      * @param string $name The name to verify
      * @access public
-     * @return bool
+     * @return boolean
      */
     public function verify($name)
     {
-        return $this->sendCommand("VRFY", "VRFY $name", array(250, 251));
+        return $this->sendCommand('VRFY', "VRFY $name", array(250, 251));
     }
 
@@ -748 +895 @@
      * Used to keep keep-alives alive, doesn't actually do anything
      * @access public
-     * @return bool
+     * @return boolean
      */
     public function noop()
     {
-        return $this->sendCommand("NOOP", "NOOP", 250);
+        return $this->sendCommand('NOOP', 'NOOP', 250);
     }
 
@@ -758 +905 @@
      * Send an SMTP TURN command.
      * This is an optional command for SMTP that this class does not support.
-     * This method is here to make the RFC821 Definition
-     * complete for this class and __may__ be implemented in future
+     * This method is here to make the RFC821 Definition complete for this class
+     * and _may_ be implemented in future
      * Implements from rfc 821: TURN <CRLF>
      * @access public
-     * @return bool
+     * @return boolean
      */
     public function turn()
     {
-        $this->error = array(
-            'error' => 'The SMTP TURN command is not implemented'
-        );
-        if ($this->do_debug >= 1) {
-            $this->edebug('SMTP -> NOTICE: ' . $this->error['error']);
-        }
+        $this->setError('The SMTP TURN command is not implemented');
+        $this->edebug('SMTP NOTICE: ' . $this->error['error'], self::DEBUG_CLIENT);
         return false;
     }
@@ -779 +922 @@
      * @param string $data The data to send
      * @access public
-     * @return int|bool The number of bytes sent to the server or FALSE on error
+     * @return integer|boolean The number of bytes sent to the server or false on error
      */
     public function client_send($data)
     {
-        if ($this->do_debug >= 1) {
-            $this->edebug("CLIENT -> SMTP: $data");
-        }
+        $this->edebug("CLIENT -> SERVER: $data", self::DEBUG_CLIENT);
         return fwrite($this->smtp_conn, $data);
     }
@@ -797 +938 @@
     {
         return $this->error;
+    }
+
+    /**
+     * Get SMTP extensions available on the server
+     * @access public
+     * @return array|null
+     */
+    public function getServerExtList()
+    {
+        return $this->server_caps;
+    }
+
+    /**
+     * A multipurpose method
+     * The method works in three ways, dependent on argument value and current state
+     *   1. HELO/EHLO was not sent - returns null and set up $this->error
+     *   2. HELO was sent
+     *     $name = 'HELO': returns server name
+     *     $name = 'EHLO': returns boolean false
+     *     $name = any string: returns null and set up $this->error
+     *   3. EHLO was sent
+     *     $name = 'HELO'|'EHLO': returns server name
+     *     $name = any string: if extension $name exists, returns boolean True
+     *       or its options. Otherwise returns boolean False
+     * In other words, one can use this method to detect 3 conditions:
+     *  - null returned: handshake was not or we don't know about ext (refer to $this->error)
+     *  - false returned: the requested feature exactly not exists
+     *  - positive value returned: the requested feature exists
+     * @param string $name Name of SMTP extension or 'HELO'|'EHLO'
+     * @return mixed
+     */
+    public function getServerExt($name)
+    {
+        if (!$this->server_caps) {
+            $this->setError('No HELO/EHLO was sent');
+            return null;
+        }
+
+        // the tight logic knot ;)
+        if (!array_key_exists($name, $this->server_caps)) {
+            if ($name == 'HELO') {
+                return $this->server_caps['EHLO'];
+            }
+            if ($name == 'EHLO' || array_key_exists('EHLO', $this->server_caps)) {
+                return false;
+            }
+            $this->setError('HELO handshake was used. Client knows nothing about server extensions');
+            return null;
+        }
+
+        return $this->server_caps[$name];
     }
 
@@ -820 +1012 @@
     protected function get_lines()
     {
+        // If the connection is bad, give up straight away
+        if (!is_resource($this->smtp_conn)) {
+            return '';
+        }
         $data = '';
         $endtime = 0;
-        // If the connection is bad, give up now
-        if (!is_resource($this->smtp_conn)) {
-            return $data;
-        }
         stream_set_timeout($this->smtp_conn, $this->Timeout);
         if ($this->Timelimit > 0) {
@@ -832 +1024 @@
         while (is_resource($this->smtp_conn) && !feof($this->smtp_conn)) {
             $str = @fgets($this->smtp_conn, 515);
-            if ($this->do_debug >= 4) {
-                $this->edebug("SMTP -> get_lines(): \$data was \"$data\"");
-                $this->edebug("SMTP -> get_lines(): \$str is \"$str\"");
-            }
+            $this->edebug("SMTP -> get_lines(): \$data is \"$data\"", self::DEBUG_LOWLEVEL);
+            $this->edebug("SMTP -> get_lines(): \$str is  \"$str\"", self::DEBUG_LOWLEVEL);
             $data .= $str;
-            if ($this->do_debug >= 4) {
-                $this->edebug("SMTP -> get_lines(): \$data is \"$data\"");
-            }
-            // if 4th character is a space, we are done reading, break the loop
-            if (substr($str, 3, 1) == ' ') {
+            // If 4th character is a space, we are done reading, break the loop, micro-optimisation over strlen
+            if ((isset($str[3]) and $str[3] == ' ')) {
                 break;
             }
@@ -847 +1034 @@
             $info = stream_get_meta_data($this->smtp_conn);
             if ($info['timed_out']) {
-                if ($this->do_debug >= 4) {
-                    $this->edebug(
-                        'SMTP -> get_lines(): timed-out (' . $this->Timeout . ' sec)'
-                    );
-                }
+                $this->edebug(
+                    'SMTP -> get_lines(): timed-out (' . $this->Timeout . ' sec)',
+                    self::DEBUG_LOWLEVEL
+                );
                 break;
             }
             // Now check if reads took too long
-            if ($endtime) {
-                if (time() > $endtime) {
-                    if ($this->do_debug >= 4) {
-                        $this->edebug(
-                            'SMTP -> get_lines(): timelimit reached ('
-                            . $this->Timelimit . ' sec)'
-                        );
-                    }
-                    break;
-                }
+            if ($endtime and time() > $endtime) {
+                $this->edebug(
+                    'SMTP -> get_lines(): timelimit reached ('.
+                    $this->Timelimit . ' sec)',
+                    self::DEBUG_LOWLEVEL
+                );
+                break;
             }
         }
@@ -872 +1055 @@
     /**
      * Enable or disable VERP address generation.
-     * @param bool $enabled
+     * @param boolean $enabled
      */
     public function setVerp($enabled = false)
@@ -881 +1064 @@
     /**
      * Get VERP address generation mode.
-     * @return bool
+     * @return boolean
      */
     public function getVerp()
@@ -889 +1072 @@
 
     /**
+     * Set error messages and codes.
+     * @param string $message The error message
+     * @param string $detail Further detail on the error
+     * @param string $smtp_code An associated SMTP error code
+     * @param string $smtp_code_ex Extended SMTP code
+     */
+    protected function setError($message, $detail = '', $smtp_code = '', $smtp_code_ex = '')
+    {
+        $this->error = array(
+            'error' => $message,
+            'detail' => $detail,
+            'smtp_code' => $smtp_code,
+            'smtp_code_ex' => $smtp_code_ex
+        );
+    }
+
+    /**
      * Set debug output method.
-     * @param string $method The function/method to use for debugging output.
+     * @param string|callable $method The name of the mechanism to use for debugging output, or a callable to handle it.
      */
     public function setDebugOutput($method = 'echo')
@@ -908 +1108 @@
     /**
      * Set debug output level.
-     * @param int $level
+     * @param integer $level
      */
     public function setDebugLevel($level = 0)
@@ -917 +1117 @@
     /**
      * Get debug output level.
-     * @return int
+     * @return integer
      */
     public function getDebugLevel()
@@ -926 +1126 @@
     /**
      * Set SMTP timeout.
-     * @param int $timeout
+     * @param integer $timeout
      */
     public function setTimeout($timeout = 0)
@@ -935 +1135 @@
     /**
      * Get SMTP timeout.
-     * @return int
+     * @return integer
      */
     public function getTimeout()
@@ -941 +1141 @@
         return $this->Timeout;
     }
+
+    /**
+     * Reports an error number and string.
+     * @param integer $errno The error number returned by PHP.
+     * @param string $errmsg The error message returned by PHP.
+     */
+    protected function errorHandler($errno, $errmsg)
+    {
+        $notice = 'Connection: Failed to connect to server.';
+        $this->setError(
+            $notice,
+            $errno,
+            $errmsg
+        );
+        $this->edebug(
+            $notice . ' Error number ' . $errno . '. "Error notice: ' . $errmsg,
+            self::DEBUG_CONNECTION
+        );
+    }
+
+    /**
+     * Will return the ID of the last smtp transaction based on a list of patterns provided
+     * in SMTP::$smtp_transaction_id_patterns.
+     * If no reply has been received yet, it will return null.
+     * If no pattern has been matched, it will return false.
+     * @return bool|null|string
+     */
+    public function getLastTransactionID()
+    {
+        $reply = $this->getLastReply();
+
+        if (empty($reply)) {
+            return null;
+        }
+
+        foreach($this->smtp_transaction_id_patterns as $smtp_transaction_id_pattern) {
+            if(preg_match($smtp_transaction_id_pattern, $reply, $matches)) {
+                return $matches[1];
+            }
+        }
+
+        return false;
+    }
 }