diff --git a/include/class.mailer.php b/include/class.mailer.php
index 4c822f725f9b80ace27d7a42b67508cbbe57bd52..cc7341b7747c2c76704bbd5b983b795a035b30e5 100644
--- a/include/class.mailer.php
+++ b/include/class.mailer.php
@@ -370,7 +370,7 @@ class Mailer {
             }
 
             // Configure the reply tag and embedded message id token
-            $mid_token = $options['thread']->asMessageId($to);
+            $mid_token = $messageId;
             if ($cfg && $cfg->stripQuotedReply()
                     && (!isset($options['reply-tag']) || $options['reply-tag']))
                 $reply_tag = $cfg->getReplySeparator() . '<br/><br/>';