Several months ago I installed a new server onto our network and installed MS Exchange 2000 onto it. The server was a first server in a new AD Domain. In the old domain, there was a 5.5 Exchange server. Some users were converted using the Migration wizard, others were created fresh (but like named accounts existed on the old domain) and there are new users. Users can send and receive email just fine, and aside from some typical hoops and quirks, everything was going along fine.
Recently we decided to try and use OWA. The long and the short of it is that some users can connect and others cannot. Those that cannot are presented with the logon screen, enter ID and password (in any of the 3 proper formats), re peat three times and then get: HTTP/1.1 401 Unauthorized. The KBs that I have found at MS relate this problem to permissions and security and I have dutifully created a Group for everyone that is going to get OWA, and applied the recommended permission to the recomended folders and made approproiate Domain settings changes in the IIS MMC. Still nothing. The server on the old domain is still powered on, but MS Exchange services ore disabled (I tried enabling certain core ones and it changed nothing). I have scoured the registry of the new server and there are no references to the old Organization or OU. Logon fails in the same manner either insode or outside the firewall.
I though for a while that the users who could not log on were of a subset that had virtually identical accounts on the old and new systems, but were not imported through Migration Wizard. However, recently I have found one that falls into this group, but can access OWA. I have checked Advanced email Features and permissions are the same for both groups of users. I am totally lost on why there is a group that cannot logon when they seemingly have the exact same rights and permissions as those who can. Any ideas?