I have just set up a new SBS 2003 server and I have a user who can no longer log in to OWA. Other users can login via OWA without problem and I have changed nothing on this account. The error is HTTP/1.1 401 Unauthorized .. They are in the relevant security groups and it has worked previously so I am not sure what is going on. The system log shows a 540 followed by a 576. They can log into the first part of RWW but not web outlook. Any ideas?

Some kind of authentication issue. Check if this user can login fine in the domain (just for testing purpose). Also see if this user has been allowed to use OWA from the exchange console.Raj

Thanks for that but I ended up just deleting and recreating the account as it was relatively new. Something definately wasnt right tho.