We recently replaced an old exchange server (srv1) with a new exchange server (srv2). So the host names have changed.
Migration was fine and mail flow works as expected, however the issue we have is that all internal outlook clients (2003/xp) are still trying to connect to old exchange hostname (srv1). So when you open outlook a login box pops up prompting for credentials and has the old hostname which is no longer online and we are having to manually update the settings for each client.
If we create a new user and connect it to outlook it pulls the proper server and autodiscover connectivity tests from the microsoft connectivity tool come back fine.
My question is: How can we either make the new server (srv2) answer requests for the old one, (srv1); or make it so that the clients automatically start going to srv2?
Turns out the client is still using Outlook 2003. We only had access to Exchange so this wasn't immediately apparent. Assuming this is the cause as it doesn't support auto-discover and everything else works correctly.
That is the expected behaviour unfortunately. You could have avoided it if you configured an RPC CAS Array. That is effectively a virtual Exchange server which exists in DNS only. Then when you moved the users to the new server, change the DNS entry and the clients follow.