I have one front-end/OWA server running Exchange 2003 standard and two back-end servers running Exchange 2003 enterprise, I can connect to my mailbox through OWA when it is on back-end server 1, but when I move my mailbox to back-end server 2, I get a HTTP/1.1 401 Unauthorized error. I can connect to my mailbox using OWA on the server locally. I have reviewed all IIS and Exchange settings on both servers and they seem to be the same. Both of the back-end servers have the same firewall rules applied. Both back-end servers have the same patches applied. I'm stumped please help.