Hi! We are current running both E2007 and E2003 in our environment. Our webmail is pointing to the E2007 cas servers that also redirects to our legacy servers. When we install our first Cas server we want to change the web mail to that server instead. We have created a legacy dns record that we will add to the Exchange2003url setting. Will the redirect still work for users running on E2003 eventhough the legacyredord is pointing to E2007 cas? And how does this work for internal users that want to use OWA with the common url used by our company? Regards, UC

Please read this wonderful team blog post by Herr Smith. http://blogs.technet.com/b/exchange/archive/2009/11/20/3408856.aspx That should answer the above, if not post back please!Cheers, Rhoderick NOTICE: My posts are provided AS IS without warranty of any kind, either expressed or implied, including but not limited to the implied warranties of merchantability and/or fitness for a particular purpose.

hi, This link also can help to answer your question. Understanding Proxying and Redirection:http://technet.microsoft.com/en-us/library/bb310763(v=exchg.80).aspx >>>And how does this work for internal users that want to use OWA with the common url used by our company? Internal access will auto proxy to the related mailbox. hope can help you thanks, CastinLu TechNet Community Support