Exchange 2007, SBS 2008...
10 users on the server, only one is having the problem.
the problem user can send emails through exchange, but is unable to receive any.
I can look at the logs and see emails for this user being 'sent', 'received' and 'delivered' but these emails do not appear in his outlook client, or in OWA.
No changes to the server have been made and all other users are not having any problems.