We just migrated from Exchange 2003 to 2007. Both the 03 and the new
07 server are still running side by side while public folder
replication occurs. The 03 exchange server is also our terminal
services computer. I upgraded Outlook to 2007 on the 03/terminal
services machine. All users except 2 had no problems on first log
in. 2 users though simply cannot connect to exchange. All I get is a
generic "unable to connect to exchange" error message when opening
outlook. Setting of the account automaticly fails or propets for
credentials which fails. I have restarted the server and verified
permissions on the autoprovision in IIS on the new exchange server.

The users normal machines upgraded to 07 fine and can connect it is
only on this PC. Installing Outllook on a fresh computer and trying
to login using one of the 2 bad users works just fine autoprovision
works great.

I have deleted the user account folder on the terminal services
machine and logged back in. It started with a fresh account settings
but still believes it cannot connect. From that user I can ping the
new email server and lookup the servers FQN.

I am clueless..... 8 other users have no problem on the same machine.