--- moodlelib.php.ori	2010-08-24 21:25:20.000000000 +0200
+++ moodlelib.php	2011-01-28 22:07:35.000000000 +0100
@@ -4275,9 +4275,15 @@
     if (is_string($from)) { // So we can pass whatever we want if there is need
         $mail->From     = $CFG->noreplyaddress;
         $mail->FromName = $from;
+        // Set Reply-To header. Some mail servers override email address of From: header.
+        // Setting Reply-To header we avoid that user replies to the overriden address
+        if(empty($replyto)) $mail->AddReplyTo($from, "Moodle");
     } else if ($usetrueaddress and $from->maildisplay) {
         $mail->From     = stripslashes($from->email);
         $mail->FromName = fullname($from);
+        // Set Reply-To header. Some mail servers override email address of From: header.
+        // Setting Reply-To header we avoid that user replies to the overriden address 
+        if(empty($replyto)) $mail->AddReplyTo($from->email, fullname($from));
     } else {
         $mail->From     = $CFG->noreplyaddress;
         $mail->FromName = fullname($from);
+        // Set Reply-To header. Some mail servers override email address of From: header.
+        // Setting Reply-To header we avoid that user replies to the overriden address 
+        if(empty($replyto)) $mail->AddReplyTo($from->email, fullname($from));