At about 3AM last night, the University's IMAP server started experiencing problems. Since then, no users will have been able to retrieve their e-mail. Outgoing e-mail should be unaffected by this problem.
On investigation this morning it was discovered that one of the four sticks of memory in the machine had developed a fault. The faulty memory has been removed and the machine is currently in the process of checking its disks prior to booting. This will take in the region of half an hour or so, after which we expect the IMAP server to be available again.
Any incomming e-mail sent during the outage will be queued by the remote mail server and will be delivered during the course of today. It may take a few hours for all remote mail servers to re-attempt delivery.