Question : Exchange 2007 and Exchange 2003 OWA question

I have deployed Exchange 2007 and have a test user mailbox on the new system.  When I log into the url for our 2003 outlook web access with this 2007 user, I am redirected to the new server, but get a 404 - File or directory not found error.

My understanding is I can have some users on 2003 and some on 2007 and use my current outlook webmail address for both.  Then depending on the user that logs in, there would be a redirection or not.

Am I correct?  Is my OWA not setup up properly?

Answer : Exchange 2007 and Exchange 2003 OWA question

It is not supported to use the old 2003 OWA URL to access a user on the Exchange 2007 system. The reason the request is failing is because the 2003 Exchange Server does not know how to resolve and communicate with the mailbox on the 2007 machine.

You will need to access at least all Exchange 2007 mailboxes using OWA on the Exchange 2007 CAS Server. This server can also proxy requests to legacy Exchange 2003 mailboxes, so I would suggest you reconfigure OWA so all users log into the CAS.

-Matt