Changeset 50397 for trunk/src/wp-includes/PHPMailer/PHPMailer.php

Timestamp:

02/21/2021 09:32:41 AM (4 years ago)

Author:

SergeyBiryukov

Message:

External Libraries: Upgrade PHPMailer to version 6.3.0.

This is a maintenance release. Changes include:

• Handle early connection errors such as 421 during connection and EHLO states.
• Make the mail() and sendmail transports set the envelope sender the same way as SMTP does, i.e. use whatever From is set to, only falling back to the sendmail_from php.ini setting if From is unset. This avoids errors from the mail() function if Sender is not set explicitly and php.ini is not configured. This is a minor functionality change, so bumps the minor version number.
• Extend parseAddresses to decode encoded names.

Release notes: ​https://github.com/PHPMailer/PHPMailer/releases/tag/v6.3.0

For a full list of changes in this update, see the PHPMailer GitHub:
​https://github.com/PHPMailer/PHPMailer/compare/v6.2.0...v6.3.0

Props ayeshrajans.
Fixes #52577.

File:

• trunk/src/wp-includes/PHPMailer/PHPMailer.php (modified) (93 diffs)

trunk/src/wp-includes/PHPMailer/PHPMailer.php

@@ -749 +749 @@
      * @var string
      */
-    const VERSION = '6.2.0';
+    const VERSION = '6.3.0';
 
     /**
@@ -863 +863 @@
         }
         //Calling mail() with null params breaks
+        $this->edebug('Sending with mail()');
+        $this->edebug('Sendmail path: ' . ini_get('sendmail_path'));
+        $this->edebug("Envelope sender: {$this->Sender}");
+        $this->edebug("To: {$to}");
+        $this->edebug("Subject: {$subject}");
+        $this->edebug("Headers: {$header}");
         if (!$this->UseSendmailOptions || null === $params) {
             $result = @mail($to, $subject, $body, $header);
         } else {
+            $this->edebug("Additional params: {$params}");
             $result = @mail($to, $subject, $body, $header, $params);
         }
-
+        $this->edebug('Result: ' . ($result ? 'true' : 'false'));
         return $result;
     }
 
     /**
-     * Output debugging info via user-defined method.
-     * Only generates output if SMTP debug output is enabled (@see SMTP::$do_debug).
+     * Output debugging info via a user-defined method.
+     * Only generates output if debug output is enabled.
      *
      * @see PHPMailer::$Debugoutput
@@ -1071 +1078 @@
         $pos = strrpos($address, '@');
         if (false === $pos) {
-            // At-sign is missing.
+            //At-sign is missing.
             $error_message = sprintf(
                 '%s (%s): %s',
@@ -1087 +1094 @@
         }
         $params = [$kind, $address, $name];
-        // Enqueue addresses with IDN until we know the PHPMailer::$CharSet.
+        //Enqueue addresses with IDN until we know the PHPMailer::$CharSet.
         if (static::idnSupported() && $this->has8bitChars(substr($address, ++$pos))) {
             if ('Reply-To' !== $kind) {
@@ -1104 +1111 @@
         }
 
-        // Immediately add standard addresses without IDN.
+        //Immediately add standard addresses without IDN.
         return call_user_func_array([$this, 'addAnAddress'], $params);
     }
@@ -1192 +1199 @@
                     )
                 ) {
+                    //Decode the name part if it's present and encoded
+                    if (property_exists($address, 'personal') && preg_match('/^=\?.*\?=$/', $address->personal)) {
+                        $address->personal = mb_decode_mimeheader($address->personal);
+                    }
+
                     $addresses[] = [
                         'name' => (property_exists($address, 'personal') ? $address->personal : ''),
@@ -1215 +1227 @@
                     list($name, $email) = explode('<', $address);
                     $email = trim(str_replace('>', '', $email));
+                    $name = trim($name);
                     if (static::validateAddress($email)) {
+                        //If this name is encoded, decode it
+                        if (preg_match('/^=\?.*\?=$/', $name)) {
+                            $name = mb_decode_mimeheader($name);
+                        }
                         $addresses[] = [
-                            'name' => trim(str_replace(['"', "'"], '', $name)),
+                            //Remove any surrounding quotes and spaces from the name
+                            'name' => trim($name, '\'" '),
                             'address' => $email,
                         ];
@@ -1243 +1261 @@
         $address = trim($address);
         $name = trim(preg_replace('/[\r\n]+/', '', $name)); //Strip breaks and trim
-        // Don't validate now addresses with IDN. Will be done in send().
+        //Don't validate now addresses with IDN. Will be done in send().
         $pos = strrpos($address, '@');
         if (
@@ -1396 +1414 @@
     public function punyencodeAddress($address)
     {
-        // Verify we have required functions, CharSet, and at-sign.
+        //Verify we have required functions, CharSet, and at-sign.
         $pos = strrpos($address, '@');
         if (
@@ -1404 +1422 @@
         ) {
             $domain = substr($address, ++$pos);
-            // Verify CharSet string is a valid one, and domain properly encoded in this CharSet.
+            //Verify CharSet string is a valid one, and domain properly encoded in this CharSet.
             if ($this->has8bitChars($domain) && @mb_check_encoding($domain, $this->CharSet)) {
-                $domain = mb_convert_encoding($domain, 'UTF-8', $this->CharSet);
+                //Convert the domain from whatever charset it's in to UTF-8
+                $domain = mb_convert_encoding($domain, self::CHARSET_UTF8, $this->CharSet);
                 //Ignore IDE complaints about this line - method signature changed in PHP 5.4
                 $errorcode = 0;
                 if (defined('INTL_IDNA_VARIANT_UTS46')) {
-                    $punycode = idn_to_ascii($domain, $errorcode, INTL_IDNA_VARIANT_UTS46);
+                    //Use the current punycode standard (appeared in PHP 7.2)
+                    $punycode = idn_to_ascii($domain, $errorcode, \INTL_IDNA_VARIANT_UTS46);
                 } elseif (defined('INTL_IDNA_VARIANT_2003')) {
+                    //Fall back to this old, deprecated/removed encoding
                     // phpcs:ignore PHPCompatibility.Constants.RemovedConstants.intl_idna_variant_2003Deprecated
-                    $punycode = idn_to_ascii($domain, $errorcode, INTL_IDNA_VARIANT_2003);
+                    $punycode = idn_to_ascii($domain, $errorcode, \INTL_IDNA_VARIANT_2003);
                 } else {
+                    //Fall back to a default we don't know about
                     // phpcs:ignore PHPCompatibility.ParameterValues.NewIDNVariantDefault.NotSet
                     $punycode = idn_to_ascii($domain, $errorcode);
@@ -1465 +1487 @@
         if (
             'smtp' === $this->Mailer
-            || ('mail' === $this->Mailer && (PHP_VERSION_ID >= 80000 || stripos(PHP_OS, 'WIN') === 0))
+            || ('mail' === $this->Mailer && (\PHP_VERSION_ID >= 80000 || stripos(PHP_OS, 'WIN') === 0))
         ) {
             //SMTP mandates RFC-compliant line endings
@@ -1477 +1499 @@
         if (
             'mail' === $this->Mailer
-            && ((PHP_VERSION_ID >= 70000 && PHP_VERSION_ID < 70017)
-                || (PHP_VERSION_ID >= 70100 && PHP_VERSION_ID < 70103))
+            && ((\PHP_VERSION_ID >= 70000 && \PHP_VERSION_ID < 70017)
+                || (\PHP_VERSION_ID >= 70100 && \PHP_VERSION_ID < 70103))
             && ini_get('mail.add_x_header') === '1'
             && stripos(PHP_OS, 'WIN') === 0
@@ -1491 +1513 @@
 
         try {
-            $this->error_count = 0; // Reset errors
+            $this->error_count = 0; //Reset errors
             $this->mailHeader = '';
 
-            // Dequeue recipient and Reply-To addresses with IDN
+            //Dequeue recipient and Reply-To addresses with IDN
             foreach (array_merge($this->RecipientsQueue, $this->ReplyToQueue) as $params) {
                 $params[1] = $this->punyencodeAddress($params[1]);
@@ -1503 +1525 @@
             }
 
-            // Validate From, Sender, and ConfirmReadingTo addresses
+            //Validate From, Sender, and ConfirmReadingTo addresses
             foreach (['From', 'Sender', 'ConfirmReadingTo'] as $address_kind) {
                 $this->$address_kind = trim($this->$address_kind);
@@ -1527 +1549 @@
             }
 
-            // Set whether the message is multipart/alternative
+            //Set whether the message is multipart/alternative
             if ($this->alternativeExists()) {
                 $this->ContentType = static::CONTENT_TYPE_MULTIPART_ALTERNATIVE;
@@ -1533 +1555 @@
 
             $this->setMessageType();
-            // Refuse to send an empty message unless we are specifically allowing it
+            //Refuse to send an empty message unless we are specifically allowing it
             if (!$this->AllowEmpty && empty($this->Body)) {
                 throw new Exception($this->lang('empty_message'), self::STOP_CRITICAL);
@@ -1540 +1562 @@
             //Trim subject consistently
             $this->Subject = trim($this->Subject);
-            // Create body before headers in case body makes changes to headers (e.g. altering transfer encoding)
+            //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
+            //createBody may have added some headers, so retain them
             $tempheaders = $this->MIMEHeader;
             $this->MIMEHeader = $this->createHeader();
             $this->MIMEHeader .= $tempheaders;
 
-            // To capture the complete message when using mail(), create
-            // an extra header list which createHeader() doesn't fold in
+            //To capture the complete message when using mail(), create
+            //an extra header list which createHeader() doesn't fold in
             if ('mail' === $this->Mailer) {
                 if (count($this->to) > 0) {
@@ -1562 +1584 @@
             }
 
-            // Sign with DKIM if enabled
+            //Sign with DKIM if enabled
             if (
                 !empty($this->DKIM_domain)
@@ -1603 +1625 @@
     {
         try {
-            // Choose the mailer and send through it
+            //Choose the mailer and send through it
             switch ($this->Mailer) {
                 case 'sendmail':
@@ -1648 +1670 @@
     protected function sendmailSend($header, $body)
     {
+        if ($this->Mailer === 'qmail') {
+            $this->edebug('Sending with qmail');
+        } else {
+            $this->edebug('Sending with sendmail');
+        }
         $header = static::stripTrailingWSP($header) . static::$LE . static::$LE;
-
-        // CVE-2016-10033, CVE-2016-10045: Don't pass -f if characters will be escaped.
-        if (!empty($this->Sender) && self::isShellSafe($this->Sender)) {
-            if ('qmail' === $this->Mailer) {
+        //This sets the SMTP envelope sender which gets turned into a return-path header by the receiver
+        //A space after `-f` is optional, but there is a long history of its presence
+        //causing problems, so we don't use one
+        //Exim docs: http://www.exim.org/exim-html-current/doc/html/spec_html/ch-the_exim_command_line.html
+        //Sendmail docs: http://www.sendmail.org/~ca/email/man/sendmail.html
+        //Qmail docs: http://www.qmail.org/man/man8/qmail-inject.html
+        //Example problem: https://www.drupal.org/node/1057954
+        //CVE-2016-10033, CVE-2016-10045: Don't pass -f if characters will be escaped.
+        if ('' === $this->Sender) {
+            $this->Sender = $this->From;
+        }
+        if (empty($this->Sender) && !empty(ini_get('sendmail_from'))) {
+            //PHP config has a sender address we can use
+            $this->Sender = ini_get('sendmail_from');
+        }
+        //CVE-2016-10033, CVE-2016-10045: Don't pass -f if characters will be escaped.
+        //But sendmail requires this param, so fail without it
+        if (!empty($this->Sender) && static::validateAddress($this->Sender) && self::isShellSafe($this->Sender)) {
+            if ($this->Mailer === 'qmail') {
                 $sendmailFmt = '%s -f%s';
             } else {
                 $sendmailFmt = '%s -oi -f%s -t';
             }
-        } elseif ('qmail' === $this->Mailer) {
-            $sendmailFmt = '%s';
         } else {
-            $sendmailFmt = '%s -oi -t';
+            $this->edebug('Sender address unusable or missing: ' . $this->Sender);
+            return false;
         }
 
         $sendmail = sprintf($sendmailFmt, escapeshellcmd($this->Sendmail), $this->Sender);
+        $this->edebug('Sendmail path: ' . $this->Sendmail);
+        $this->edebug('Sendmail command: ' . $sendmail);
+        $this->edebug('Envelope sender: ' . $this->Sender);
+        $this->edebug("Headers: {$header}");
 
         if ($this->SingleTo) {
@@ -1671 +1716 @@
                     throw new Exception($this->lang('execute') . $this->Sendmail, self::STOP_CRITICAL);
                 }
+                $this->edebug("To: {$toAddr}");
                 fwrite($mail, 'To: ' . $toAddr . "\n");
                 fwrite($mail, $header);
@@ -1685 +1731 @@
                     []
                 );
+                $this->edebug("Result: " . ($result === 0 ? 'true' : 'false'));
                 if (0 !== $result) {
                     throw new Exception($this->lang('execute') . $this->Sendmail, self::STOP_CRITICAL);
@@ -1707 +1754 @@
                 []
             );
+            $this->edebug("Result: " . ($result === 0 ? 'true' : 'false'));
             if (0 !== $result) {
                 throw new Exception($this->lang('execute') . $this->Sendmail, self::STOP_CRITICAL);
@@ -1727 +1775 @@
     protected static function isShellSafe($string)
     {
-        // Future-proof
+        //Future-proof
         if (
             escapeshellcmd($string) !== $string
@@ -1740 +1788 @@
             $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.
+            //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('@_-.', $c) === false) {
                 return false;
@@ -1812 +1860 @@
         //Qmail docs: http://www.qmail.org/man/man8/qmail-inject.html
         //Example problem: https://www.drupal.org/node/1057954
-        // CVE-2016-10033, CVE-2016-10045: Don't pass -f if characters will be escaped.
-        if (!empty($this->Sender) && static::validateAddress($this->Sender) && self::isShellSafe($this->Sender)) {
-            $params = sprintf('-f%s', $this->Sender);
+        //CVE-2016-10033, CVE-2016-10045: Don't pass -f if characters will be escaped.
+        if ('' === $this->Sender) {
+            $this->Sender = $this->From;
+        }
+        if (empty($this->Sender) && !empty(ini_get('sendmail_from'))) {
+            //PHP config has a sender address we can use
+            $this->Sender = ini_get('sendmail_from');
         }
         if (!empty($this->Sender) && static::validateAddress($this->Sender)) {
+            if (self::isShellSafe($this->Sender)) {
+                $params = sprintf('-f%s', $this->Sender);
+            }
             $old_from = ini_get('sendmail_from');
             ini_set('sendmail_from', $this->Sender);
@@ -1902 +1957 @@
 
         $callbacks = [];
-        // Attempt to send to all recipients
+        //Attempt to send to all recipients
         foreach ([$this->to, $this->cc, $this->bcc] as $togroup) {
             foreach ($togroup as $to) {
@@ -1917 +1972 @@
         }
 
-        // Only send the DATA command if we have viable recipients
+        //Only send the DATA command if we have viable recipients
         if ((count($this->all_recipients) > count($bad_rcpt)) && !$this->smtp->data($header . $body)) {
             throw new Exception($this->lang('data_not_accepted'), self::STOP_CRITICAL);
@@ -1979 +2034 @@
         }
 
-        // Already connected?
+        //Already connected?
         if ($this->smtp->connected()) {
             return true;
@@ -2001 +2056 @@
             ) {
                 $this->edebug($this->lang('invalid_hostentry') . ' ' . trim($hostentry));
-                // Not a valid host entry
+                //Not a valid host entry
                 continue;
             }
-            // $hostinfo[1]: optional ssl or tls prefix
-            // $hostinfo[2]: the hostname
-            // $hostinfo[3]: optional port number
-            // The host string prefix can temporarily override the current setting for SMTPSecure
-            // If it's not specified, the default value is used
+            //$hostinfo[1]: optional ssl or tls prefix
+            //$hostinfo[2]: the hostname
+            //$hostinfo[3]: 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
 
             //Check the host name is a valid name or IP address before trying to use it
@@ -2020 +2075 @@
             if ('ssl' === $hostinfo[1] || ('' === $hostinfo[1] && static::ENCRYPTION_SMTPS === $this->SMTPSecure)) {
                 $prefix = 'ssl://';
-                $tls = false; // Can't have SSL and TLS at the same time
+                $tls = false; //Can't have SSL and TLS at the same time
                 $secure = static::ENCRYPTION_SMTPS;
             } elseif ('tls' === $hostinfo[1]) {
                 $tls = true;
-                // tls doesn't use a prefix
+                //TLS doesn't use a prefix
                 $secure = static::ENCRYPTION_STARTTLS;
             }
@@ -2054 +2109 @@
                     $this->smtp->hello($hello);
                     //Automatically enable TLS encryption if:
-                    // * it's not disabled
-                    // * we have openssl extension
-                    // * we are not already using SSL
-                    // * the server offers STARTTLS
+                    //* it's not disabled
+                    //* we have openssl extension
+                    //* we are not already using SSL
+                    //* the server offers STARTTLS
                     if ($this->SMTPAutoTLS && $sslext && 'ssl' !== $secure && $this->smtp->getServerExt('STARTTLS')) {
                         $tls = true;
@@ -2065 +2120 @@
                             throw new Exception($this->lang('connect_host'));
                         }
-                        // We must resend EHLO after TLS negotiation
+                        //We must resend EHLO after TLS negotiation
                         $this->smtp->hello($hello);
                     }
@@ -2083 +2138 @@
                     $lastexception = $exc;
                     $this->edebug($exc->getMessage());
-                    // We must have connected, but then failed TLS or Auth, so close connection nicely
+                    //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 && null !== $lastexception) {
             throw $lastexception;
@@ -2121 +2176 @@
     public function setLanguage($langcode = 'en', $lang_path = '')
     {
-        // Backwards compatibility for renamed language codes
+        //Backwards compatibility for renamed language codes
         $renamed_langcodes = [
             'br' => 'pt_br',
@@ -2137 +2192 @@
         }
 
-        // Define full set of translatable strings in English
+        //Define full set of translatable strings in English
         $PHPMAILER_LANG = [
             'authenticate' => 'SMTP Error: Could not authenticate.',
@@ -2162 +2217 @@
         ];
         if (empty($lang_path)) {
-            // Calculate an absolute path so it can work if CWD is not here
+            //Calculate an absolute path so it can work if CWD is not here
             $lang_path = dirname(__DIR__) . DIRECTORY_SEPARATOR . 'language' . DIRECTORY_SEPARATOR;
         }
@@ -2171 +2226 @@
         $foundlang = true;
         $lang_file = $lang_path . 'phpmailer.lang-' . $langcode . '.php';
-        // There is no English translation file
+        //There is no English translation file
         if ('en' !== $langcode) {
-            // Make sure language file path is readable
+            //Make sure language file path is readable
             if (!static::fileIsAccessible($lang_file)) {
                 $foundlang = false;
             } else {
-                // Overwrite language-specific strings.
-                // This way we'll never have missing translation keys.
+                //Overwrite language-specific strings.
+                //This way we'll never have missing translation keys.
                 $foundlang = include $lang_file;
             }
@@ -2184 +2239 @@
         $this->language = $PHPMAILER_LANG;
 
-        return (bool) $foundlang; // Returns false if language not found
+        return (bool) $foundlang; //Returns false if language not found
     }
 
@@ -2228 +2283 @@
     public function addrFormat($addr)
     {
-        if (empty($addr[1])) { // No name provided
+        if (empty($addr[1])) { //No name provided
             return $this->secureHeader($addr[0]);
         }
@@ -2255 +2310 @@
             $soft_break = static::$LE;
         }
-        // If utf-8 encoding is used, we will need to make sure we don't
-        // split multibyte characters when we wrap
+        //If utf-8 encoding is used, we will need to make sure we don't
+        //split multibyte characters when we wrap
         $is_utf8 = static::CHARSET_UTF8 === strtolower($this->CharSet);
         $lelen = strlen(static::$LE);
@@ -2356 +2411 @@
             $encodedCharPos = strpos($lastChunk, '=');
             if (false !== $encodedCharPos) {
-                // Found start of encoded character byte within $lookBack block.
-                // Check the encoded byte value (the 2 chars after the '=')
+                //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 ($dec < 128) {
-                    // Single byte character.
-                    // If the encoded char was found at pos 0, it will fit
-                    // otherwise reduce maxLength to start of the encoded char
+                    //Single byte character.
+                    //If the encoded char was found at pos 0, it will fit
+                    //otherwise reduce maxLength to start of the encoded char
                     if ($encodedCharPos > 0) {
                         $maxLength -= $lookBack - $encodedCharPos;
@@ -2369 +2424 @@
                     $foundSplitPos = true;
                 } elseif ($dec >= 192) {
-                    // First byte of a multi byte character
-                    // Reduce maxLength to split at start of character
+                    //First byte of a multi byte character
+                    //Reduce maxLength to split at start of character
                     $maxLength -= $lookBack - $encodedCharPos;
                     $foundSplitPos = true;
                 } elseif ($dec < 192) {
-                    // Middle byte of a multi byte character, look further back
+                    //Middle byte of a multi byte character, look further back
                     $lookBack += 3;
                 }
             } else {
-                // No encoded character found
+                //No encoded character found
                 $foundSplitPos = true;
             }
@@ -2422 +2477 @@
         $result .= $this->headerLine('Date', '' === $this->MessageDate ? self::rfcDate() : $this->MessageDate);
 
-        // The To header is created automatically by mail(), so needs to be omitted here
+        //The To header is created automatically by mail(), so needs to be omitted here
         if ('mail' !== $this->Mailer) {
             if ($this->SingleTo) {
@@ -2436 +2491 @@
         $result .= $this->addrAppend('From', [[trim($this->From), $this->FromName]]);
 
-        // sendmail and mail() extract Cc from the header before sending
+        //sendmail and mail() extract Cc from the header before sending
         if (count($this->cc) > 0) {
             $result .= $this->addrAppend('Cc', $this->cc);
         }
 
-        // sendmail and mail() extract Bcc from the header before sending
+        //sendmail and mail() extract Bcc from the header before sending
         if (
             (
@@ -2455 +2510 @@
         }
 
-        // mail() sets the subject itself
+        //mail() sets the subject itself
         if ('mail' !== $this->Mailer) {
             $result .= $this->headerLine('Subject', $this->encodeHeader($this->secureHeader($this->Subject)));
         }
 
-        // 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
+        //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 ('' !== $this->MessageID && preg_match('/^<.*@.*>$/', $this->MessageID)) {
             $this->lastMessageID = $this->MessageID;
@@ -2487 +2542 @@
         }
 
-        // Add custom headers
+        //Add custom headers
         foreach ($this->CustomHeader as $header) {
             $result .= $this->headerLine(
@@ -2529 +2584 @@
                 break;
             default:
-                // Catches case 'plain': and case '':
+                //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 (static::ENCODING_7BIT !== $this->Encoding) {
-            // RFC 2045 section 6.4 says multipart MIME parts may only use 7bit, 8bit or binary CTE
+            //RFC 2045 section 6.4 says multipart MIME parts may only use 7bit, 8bit or binary CTE
             if ($ismultipart) {
                 if (static::ENCODING_8BIT === $this->Encoding) {
                     $result .= $this->headerLine('Content-Transfer-Encoding', static::ENCODING_8BIT);
                 }
-                // The only remaining alternatives are quoted-printable and base64, which are both 7bit compatible
+                //The only remaining alternatives are quoted-printable and base64, which are both 7bit compatible
             } else {
                 $result .= $this->headerLine('Content-Transfer-Encoding', $this->Encoding);
             }
-        }
-
-        if ('mail' !== $this->Mailer) {
-//            $result .= static::$LE;
         }
 
@@ -2819 +2870 @@
                 break;
             default:
-                // Catch case 'plain' and case '', applies to simple `text/plain` and `text/html` body content types
+                //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;
@@ -2910 +2961 @@
         $result .= sprintf('Content-Type: %s; charset=%s', $contentType, $charSet);
         $result .= static::$LE;
-        // RFC1341 part 5 says 7bit is assumed if not specified
+        //RFC1341 part 5 says 7bit is assumed if not specified
         if (static::ENCODING_7BIT !== $encoding) {
             $result .= $this->headerLine('Content-Transfer-Encoding', $encoding);
@@ -3008 +3059 @@
             }
 
-            // 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) {
                 $type = static::filenameToType($path);
@@ -3027 +3078 @@
                 3 => $encoding,
                 4 => $type,
-                5 => false, // isStringAttachment
+                5 => false, //isStringAttachment
                 6 => $disposition,
                 7 => $name,
@@ -3067 +3118 @@
     protected function attachAll($disposition_type, $boundary)
     {
-        // Return text of body
+        //Return text of body
         $mime = [];
         $cidUniq = [];
         $incl = [];
 
-        // Add all attachments
+        //Add all attachments
         foreach ($this->attachment as $attachment) {
-            // Check if it is a valid disposition_filter
+            //Check if it is a valid disposition_filter
             if ($attachment[6] === $disposition_type) {
-                // Check for string attachment
+                //Check for string attachment
                 $string = '';
                 $path = '';
@@ -3117 +3168 @@
                     );
                 }
-                // RFC1341 part 5 says 7bit is assumed if not specified
+                //RFC1341 part 5 says 7bit is assumed if not specified
                 if (static::ENCODING_7BIT !== $encoding) {
                     $mime[] = sprintf('Content-Transfer-Encoding: %s%s', $encoding, static::$LE);
@@ -3127 +3178 @@
                 }
 
-                // Allow for bypassing the Content-Disposition header
+                //Allow for bypassing the Content-Disposition header
                 if (!empty($disposition)) {
                     $encoded_name = $this->encodeHeader($this->secureHeader($name));
@@ -3148 +3199 @@
                 }
 
-                // Encode as string attachment
+                //Encode as string attachment
                 if ($bString) {
                     $mime[] = $this->encodeString($string, $encoding);
@@ -3224 +3275 @@
             case static::ENCODING_8BIT:
                 $encoded = static::normalizeBreaks($str);
-                // Make sure it ends with a line break
+                //Make sure it ends with a line break
                 if (substr($encoded, -(strlen(static::$LE))) !== static::$LE) {
                     $encoded .= static::$LE;
@@ -3262 +3313 @@
             case 'phrase':
                 if (!preg_match('/[\200-\377]/', $str)) {
-                    // Can't use addslashes as we don't know the value of 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)) {
@@ -3288 +3339 @@
         }
 
-        // Q/B encoding adds 8 chars and the charset ("` =?<charset>?[QB]?<content>?=`").
+        //Q/B encoding adds 8 chars and the charset ("` =?<charset>?[QB]?<content>?=`").
         $overhead = 8 + strlen($charset);
 
@@ -3297 +3348 @@
         }
 
-        // Select the encoding that produces the shortest output and/or prevents corruption.
+        //Select the encoding that produces the shortest output and/or prevents corruption.
         if ($matchcount > strlen($str) / 3) {
-            // More than 1/3 of the content needs encoding, use B-encode.
+            //More than 1/3 of the content needs encoding, use B-encode.
             $encoding = 'B';
         } elseif ($matchcount > 0) {
-            // Less than 1/3 of the content needs encoding, use Q-encode.
+            //Less than 1/3 of the content needs encoding, use Q-encode.
             $encoding = 'Q';
         } elseif (strlen($str) > $maxlen) {
-            // No encoding needed, but value exceeds max line length, use Q-encode to prevent corruption.
+            //No encoding needed, but value exceeds max line length, use Q-encode to prevent corruption.
             $encoding = 'Q';
         } else {
-            // No reformatting needed
+            //No reformatting needed
             $encoding = false;
         }
@@ -3315 +3366 @@
             case 'B':
                 if ($this->hasMultiBytes($str)) {
-                    // Use a custom function which correctly encodes and wraps long
-                    // multibyte strings without breaking lines within a character
+                    //Use a custom function which correctly encodes and wraps long
+                    //multibyte strings without breaking lines within a character
                     $encoded = $this->base64EncodeWrapMB($str, "\n");
                 } else {
@@ -3351 +3402 @@
         }
 
-        // Assume no multibytes (we can't handle without mbstring functions anyway)
+        //Assume no multibytes (we can't handle without mbstring functions anyway)
         return false;
     }
@@ -3389 +3440 @@
 
         $mb_length = mb_strlen($str, $this->CharSet);
-        // Each line must have length <= 75, including $start and $end
+        //Each line must have length <= 75, including $start and $end
         $length = 75 - strlen($start) - strlen($end);
-        // Average multi-byte ratio
+        //Average multi-byte ratio
         $ratio = $mb_length / strlen($str);
-        // Base64 has a 4:3 ratio
+        //Base64 has a 4:3 ratio
         $avgLength = floor($length * $ratio * .75);
 
@@ -3408 +3459 @@
         }
 
-        // Chomp the last linefeed
+        //Chomp the last linefeed
         return substr($encoded, 0, -strlen($linebreak));
     }
@@ -3437 +3488 @@
     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(["\r", "\n"], '', $str);
         switch (strtolower($position)) {
             case 'phrase':
-                // RFC 2047 section 5.3
+                //RFC 2047 section 5.3
                 $pattern = '^A-Za-z0-9!*+\/ -';
                 break;
@@ -3455 +3506 @@
             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;
@@ -3462 +3513 @@
         $matches = [];
         if (preg_match_all("/[{$pattern}]/", $encoded, $matches)) {
-            // If the string contains an '=', make sure it's the first thing we replace
-            // so as to avoid double-encoding
+            //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], true);
             if (false !== $eqkey) {
@@ -3473 +3524 @@
             }
         }
-        // Replace spaces with _ (more readable than =20)
-        // RFC 2047 section 4.2(2)
+        //Replace spaces with _ (more readable than =20)
+        //RFC 2047 section 4.2(2)
         return str_replace(' ', '_', $encoded);
     }
@@ -3501 +3552 @@
     ) {
         try {
-            // 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) {
                 $type = static::filenameToType($filename);
@@ -3510 +3561 @@
             }
 
-            // Append to $attachment array
+            //Append to $attachment array
             $this->attachment[] = [
                 0 => $string,
@@ -3517 +3568 @@
                 3 => $encoding,
                 4 => $type,
-                5 => true, // isStringAttachment
+                5 => true, //isStringAttachment
                 6 => $disposition,
                 7 => 0,
@@ -3568 +3619 @@
             }
 
-            // 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) {
                 $type = static::filenameToType($path);
@@ -3582 +3633 @@
             }
 
-            // Append to $attachment array
+            //Append to $attachment array
             $this->attachment[] = [
                 0 => $path,
@@ -3589 +3640 @@
                 3 => $encoding,
                 4 => $type,
-                5 => false, // isStringAttachment
+                5 => false, //isStringAttachment
                 6 => $disposition,
                 7 => $cid,
@@ -3634 +3685 @@
     ) {
         try {
-            // If a MIME type is not specified, try to work it out from the name
+            //If a MIME type is not specified, try to work it out from the name
             if ('' === $type && !empty($name)) {
                 $type = static::filenameToType($name);
@@ -3643 +3694 @@
             }
 
-            // Append to $attachment array
+            //Append to $attachment array
             $this->attachment[] = [
                 0 => $string,
@@ -3650 +3701 @@
                 3 => $encoding,
                 4 => $type,
-                5 => true, // isStringAttachment
+                5 => true, //isStringAttachment
                 6 => $disposition,
                 7 => $cid,
@@ -3870 +3921 @@
     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());
 
@@ -3949 +4000 @@
     {
         if (count($this->language) < 1) {
-            $this->setLanguage(); // set the default language
+            $this->setLanguage(); //Set the default language
         }
 
         if (array_key_exists($key, $this->language)) {
             if ('smtp_connect_failed' === $key) {
-                //Include a link to troubleshooting docs on SMTP connection failure
-                //this is by far the biggest cause of support questions
+                //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';
@@ -3990 +4041 @@
     {
         if (null === $value && strpos($name, ':') !== false) {
-            // Value passed in as name:value
+            //Value passed in as name:value
             list($name, $value) = explode(':', $name, 2);
         }
@@ -4044 +4095 @@
         if (array_key_exists(2, $images)) {
             if (strlen($basedir) > 1 && '/' !== substr($basedir, -1)) {
-                // Ensure $basedir has a trailing /
+                //Ensure $basedir has a trailing /
                 $basedir .= '/';
             }
             foreach ($images[2] as $imgindex => $url) {
-                // Convert data URIs into embedded images
+                //Convert data URIs into embedded images
                 //e.g. "data:image/gif;base64,R0lGODlhAQABAAAAACH5BAEKAAEALAAAAAABAAEAAAICTAEAOw=="
                 $match = [];
@@ -4062 +4113 @@
                     //Hash the decoded data, not the URL, so that the same data-URI image used in multiple places
                     //will only be embedded once, even if it used a different encoding
-                    $cid = substr(hash('sha256', $data), 0, 32) . '@phpmailer.0'; // RFC2392 S 2
+                    $cid = substr(hash('sha256', $data), 0, 32) . '@phpmailer.0'; //RFC2392 S 2
 
                     if (!$this->cidExists($cid)) {
@@ -4081 +4132 @@
                 }
                 if (
-                    // Only process relative URLs if a basedir is provided (i.e. no absolute local paths)
+                    //Only process relative URLs if a basedir is provided (i.e. no absolute local paths)
                     !empty($basedir)
-                    // Ignore URLs containing parent dir traversal (..)
+                    //Ignore URLs containing parent dir traversal (..)
                     && (strpos($url, '..') === false)
-                    // Do not change urls that are already inline images
+                    //Do not change urls that are already inline images
                     && 0 !== strpos($url, 'cid:')
-                    // Do not change absolute URLs, including anonymous protocol
+                    //Do not change absolute URLs, including anonymous protocol
                     && !preg_match('#^[a-z][a-z0-9+.-]*:?//#i', $url)
                 ) {
@@ -4095 +4146 @@
                         $directory = '';
                     }
-                    // RFC2392 S 2
+                    //RFC2392 S 2
                     $cid = substr(hash('sha256', $url), 0, 32) . '@phpmailer.0';
                     if (strlen($basedir) > 1 && '/' !== substr($basedir, -1)) {
@@ -4122 +4173 @@
         }
         $this->isHTML();
-        // Convert all message body line breaks to LE, makes quoted-printable encoding work much better
+        //Convert all message body line breaks to LE, makes quoted-printable encoding work much better
         $this->Body = static::normalizeBreaks($message);
         $this->AltBody = static::normalizeBreaks($this->html2text($message, $advanced));
@@ -4141 +4192 @@
      *
      * ```php
-     * // Use default conversion
+     * //Use default conversion
      * $plain = $mail->html2text($html);
-     * // Use your own custom converter
+     * //Use your own custom converter
      * $plain = $mail->html2text($html, function($html) {
      *     $converter = new MyHtml2text($html);
@@ -4310 +4361 @@
     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 (false !== $qpos) {
@@ -4421 +4472 @@
             $breaktype = static::$LE;
         }
-        // Normalise to \n
+        //Normalise to \n
         $text = str_replace([self::CRLF, "\r"], "\n", $text);
-        // Now convert LE as needed
+        //Now convert LE as needed
         if ("\n" !== $breaktype) {
             $text = str_replace("\n", $breaktype, $text);
@@ -4529 +4580 @@
         }
         if (openssl_sign($signHeader, $signature, $privKey, 'sha256WithRSAEncryption')) {
-            if (PHP_MAJOR_VERSION < 8) {
+            if (\PHP_MAJOR_VERSION < 8) {
                 openssl_pkey_free($privKey);
             }
@@ -4535 +4586 @@
             return base64_encode($signature);
         }
-        if (PHP_MAJOR_VERSION < 8) {
+        if (\PHP_MAJOR_VERSION < 8) {
             openssl_pkey_free($privKey);
         }
@@ -4602 +4653 @@
             return self::CRLF;
         }
-        // Normalize line endings to CRLF
+        //Normalize line endings to CRLF
         $body = static::normalizeBreaks($body, self::CRLF);
 
@@ -4622 +4673 @@
     public function DKIM_Add($headers_line, $subject, $body)
     {
-        $DKIMsignatureType = 'rsa-sha256'; // Signature & hash algorithms
-        $DKIMcanonicalization = 'relaxed/simple'; // Canonicalization methods of header & body
-        $DKIMquery = 'dns/txt'; // Query method
+        $DKIMsignatureType = 'rsa-sha256'; //Signature & hash algorithms
+        $DKIMcanonicalization = 'relaxed/simple'; //Canonicalization methods of header & body
+        $DKIMquery = 'dns/txt'; //Query method
         $DKIMtime = time();
         //Always sign these headers without being asked
@@ -4725 +4776 @@
         $headerValues = implode(static::$LE, $headersToSign);
         $body = $this->DKIM_BodyC($body);
-        $DKIMb64 = base64_encode(pack('H*', hash('sha256', $body))); // Base64 of packed binary SHA-256 hash of body
+        //Base64 of packed binary SHA-256 hash of body
+        $DKIMb64 = base64_encode(pack('H*', hash('sha256', $body)));
         $ident = '';
         if ('' !== $this->DKIM_identity) {