Notification list don't work

I set up the notification list to send me an e-mail whenever a virus event is triggered. Unforatunately the notification don't work. I go to the Sophos test site and clicked on the eicar virus. The event was in the logs but it was not send via mail. I guess there is something wrong... [:O]

The automatic backups are still send via mail without any problems so my mail server configuration seems correct.