Add pointy brackets to recipient adress of email notifications

[mnaef]

HTML emails trigger the TO_NO_BRKTS_HTML_ONLY (To: misformatted and HTML only) Spamassassin rule which scores 2 points.

Solution for mails being sent via php mail function:

--- ./wp-includes/class-phpmailer.old.php       2015-09-21 17:10:09.019559000 +0200
+++ ./wp-includes/class-phpmailer.php   2015-09-21 17:10:39.257980000 +0200
@@ -647,9 +647,9 @@
             $subject = $this->encodeHeader($this->secureHeader($subject));
         }
         if (ini_get('safe_mode') || !($this->UseSendmailOptions)) {
-            $result = @mail($to, $subject, $body, $header);
+            $result = @mail('<'.$to.'>', $subject, $body, $header);
         } else {
-            $result = @mail($to, $subject, $body, $header, $params);
+            $result = @mail('<'.$to.'>', $subject, $body, $header, $params);
         }
         return $result;
     }

[swissspidy]

It should be noted that PHPMailer is an external class, so we can't simply change things there.

TO_NO_BRKTS_HTML_ONLY means: To: misformatted and HTML only.

So one problem is that you're sending HTML emails without a text fallback and you're passing misformatted addresses. Instead of test@example.com it should be John Doe <test@example.com> or test@example.com <test@example.com>. Either formatted email address can be passed to wp_mail().

Related: #17305

[cbutlerjr]

It should be noted that PHPMailer is an external class, so we can't simply change things there.

Based on that and the fact that this is due to passing misformatted addresses, should this be closed?