I have a WAN running 9 DC and 1 Exchange 2003 Svr. The servers are all running Windows 2003 Std Ed, some with and some without SP1 on them. I have one Exchange 2003 Std Ed SP2 running. Exchange appears to be working without a problem. It is collecting, sending and passing email. All services are running and all stores are mounting etc. Some of the servers are communicating with Exchange via a VPN tunnel. The tunnels are up and servers on either side of the tunnel are working. I've checked and all servers and workstations in question can communicate (ping) the Exchange server properly.
My question is this: At a few of the remote branches (not all of them) when the users login to the domain and they launch Outlook 2003, they are prompted for there username and password. Even with correct information and the correct format, they are unable to connect to Exchange. This isn't happening at all branches and is not happening on the LAN where the Exch. svr is located.
I've never seen this before, so I thought I would send it to the best of the best.