Ok...here we go.
First of all this is SBS 2003 with Exchange 2003. (I know......)
This case came across my desk as a new user that was create did not have an associated email account.
I verified this to be the case and did an update on the Recipient Update Service. Now when I create a user, both the account and mailbox are created.
The issue I'm running into is that after the mailbox is created, the user cannot connect to it.
I have rebooted the server, had another user log onto this workstation to rule out that as an issue.
I can connect to the mailbox and successfully send/receive using OWA when directly on the server. The user cannot connect to the mailbox via OWA from his workstation.
I've been scouring both EE and the internet for 2 weeks trying to find a solution to no avail.
The only thing I haven't tried that I saw worked for one person was to run ESEUTIL and ISINTEG on the Exchange DB. This really isn't an option as my customer doesn't have the storage space and can't have their email system down for that long unless I am 100% sure this will fix the issue.
The other thing I haven't been able to get the user to try is to sign onto another machine with his credentials to see if it's an issue with his Windows profile. I'm working on that now.
If anybody has something else please let me know.