[2010-04-28 14:30:48 | Lars Rohrbach]
Normal IMAP service has been restored.
The problem appears to be storage-related. File system access issues (stale NFS file handles) led to the imap server accepting incoming email but not being able to deliver to people’s inboxes.
Before the message serving processes were stopped and restarted and file systems remounted, there were over 3500 messages stuck in the queue for delivery to people’s inboxes.
No email was lost, and all queued email has now been delivered.
Resolved as of 2010-04-28 14:12:00