diff --git a/include/class.thread.php b/include/class.thread.php
index 94ffe4be037d89e155dcf06f56a1fbc5e260fbf0..551d8b8e7ea6fda6132f427bee3e98dc09a7a075 100644
--- a/include/class.thread.php
+++ b/include/class.thread.php
@@ -564,6 +564,11 @@ implements Searchable {
             $vars['thread-type'] = 'M';
         }
 
+        if ($mailinfo['system_emails']
+                && ($t = $this->getObject())
+                && $t instanceof Ticket)
+            $t->systemReferral($mailinfo['system_emails']);
+
         switch ($vars['thread-type']) {
         case 'M':
             $vars['message'] = $body;