I have an SBS 2003 server running Exchange 2003 SP2. We have been using Activesync with windows mobile devices for the past 2 years. Starting yesterday, one of the user's phones will no longer sync mail. It still sync's contacts & calandar items, just not mail. During the sync, it will say that it is downloading 0 of 21 items, and stay there forever. I have deleted the mail account from the phone and recreated it, same issue.
The only error I am getting on the server is: Event ID: 3005
Unexpected Exchange mailbox Server error: Server: [server.domain.local] User: [firstname.lastname@example.org] HTTP status code: . Verify that the Exchange mailbox Server is working correctly.