I had a RAID 10 lose two drives, so I had to restore SBS 2003 from the most recent backup. When I did, one user stopped receiving email. He could send without issue, and Outlook said he was connected. Turns out the mail is sitting in the local delivery queue. All the mail in there is for that one user.
I tried to repair the mailstore database. no change.
I created a new user and moved all the email aliases over. Seemed to work, but then noticed that some email was still getting hung up in the local delivery queue. Even when local users send email, it doesn't always go through.
It does not matter which computer he logs into.