Between 18 Jul 2011 14:00 and 21 Jul 2011 11:00, a number of e-mails from CERN to e-mail addresses @physik.uni-muenchen.de were either significantly delayed or failed to be delivered.

The problem was caused by a mail server on one of the two paths an e-mail can travel between CERN and physik.uni-muenchen.de. Hence about half the messages sent from CERN to e-mail addresses @physik.uni-muenchen.de since Monday were affected.

1200 e-mails have been delayed; they were eventually delivered by 21 Jul 2011 11:00 once the problem was identified and resolved.

An additional 430 e-mails were delayed for too long and were finally abandoned. For these messages, the senders received a "Non-Delivery Report" indicating that delivery to some recipients @physik.uni-muenchen.de had failed. In this case, the senders are invited to re-send the message that could not be delivered.