- Patch #330084 by c960657: don't set Reply-To header unless necessary and fixed documentation issue.

includes/mail.inc

@@ -70,7 +70,7 @@
  * @param $params
  *   Optional parameters to build the e-mail.
  * @param $from
- *   Sets From, Reply-To, Return-Path and Error-To to this value, if given.
+ *   Sets From to this value, if given.
  * @param $send
  *   Send the message directly, without calling drupal_mail_send() manually.
  * @return
@@ -105,10 +105,10 @@ function drupal_mail($module, $key, $to, $language, $params = array(), $from = N
     // To prevent e-mail from looking like spam, the addresses in the Sender and
     // Return-Path headers should have a domain authorized to use the originating
     // SMTP server. Errors-To is redundant, but shouldn't hurt.
-    $headers['From'] = $headers['Reply-To'] = $headers['Sender'] = $headers['Return-Path'] = $headers['Errors-To'] = $default_from;
+    $headers['From'] = $headers['Sender'] = $headers['Return-Path'] = $headers['Errors-To'] = $default_from;
   }
   if ($from) {
-    $headers['From'] = $headers['Reply-To'] = $from;
+    $headers['From'] = $from;
   }
   $message['headers'] = $headers;