Index: pm_email_notify/pm_email_notify.module
===================================================================
RCS file: /cvs/drupal/contributions/modules/privatemsg/pm_email_notify/pm_email_notify.module,v
retrieving revision 1.17
diff -u -p -r1.17 pm_email_notify.module
--- pm_email_notify/pm_email_notify.module	29 Nov 2010 07:57:05 -0000	1.17
+++ pm_email_notify/pm_email_notify.module	8 Feb 2011 12:18:00 -0000
@@ -56,7 +56,8 @@ function pm_email_notify_privatemsg_mess
       // send them a new pm notification email if they did
       $params['recipient'] = $recipient;
       $params['message'] = $message;
-      drupal_mail('pm_email_notify', 'notice', $recipient->mail, user_preferred_language($recipient), $params, variable_get('pm_email_notify_from',''));
+      $from = !empty(variable_get('pm_email_notify_from', '')) ? variable_get('pm_email_notify_from', '') : NULL;
+      drupal_mail('pm_email_notify', 'notice', $recipient->mail, user_preferred_language($recipient), $params, $from);
     }
   }
 }