The Exchange server 2003 froze and crashed 2 days ago during an online database backup that was frozen. Users started complaining that they could not open their mailboxes. I restarted the domain controllers and the exchange server and then users could access their mailboxes again. Later that day, the server rebooted itself for no reason and the event log indicated "recovery complete". The problem for users came back - no one could open their mailbox except for administrators. I have tried creating a new user and mailbox and I have to add the user to the domain admins group or they cannot open the mailbox. I have mailbox logging and access control set to maximum. Nothing shows up unless you open the mailbox as an administrator and then an entry shows up in the event log. It seems the exchange server will not let regular users connect at all. Note - I had opened a question 2 days ago and prematurely thought my problem was solved, but it appears to be a bigger problem than I originally thought. Any ideas?