Hi, I've deployed an Exchange 2010 server in my existing Exchange 2003 org, and until now, moved only some mailboxes from 2003 to 2010. If some Ex2003 customers use Ex2010 OWA to log in (from outside the AD domain), I've set the correct setting with Set-OWAVirtualDirectory -Exchange2003Url -LegacyRedirection, so that they get redirected to the Ex2003 OWA URL. So far so good Though, when Ex2010 customers use Ex2003 OWA, they are redirected to the internal Ex2010 OWA URL. Bad luck given, as I said, that they're outside the domain. Any idea how to tell Ex2003 which specific URL to use ? Thanks Christian

Ex2010 users need to use the 2010 OWA address. If they log into 2003 OWA it will not redirect them to 2010. Give all users the 2010 OWA URL and everything will work (2003 users get redirected and 2010 users are happy).Tim Harrington - Catapult Systems - http://HowDoUC.blogspot.com

What do you have set for the externalURL on the 2010 CAS?

It is set to http://exchange.mydomain.fr/owa, which works fine when typed in a web browser. The behaviour I'd expect would only be temporary. But given that most of customers are away on vacation, I'd like them - at least those still on Ex2003 - to be transparently redirected, though this is no big deal in our situation.

Well, it wont work w/o an extra step from the user when they connect to the legacy OWA frontend first - but - that is why you move the DNS namespace of the old 2003 OWA to the new 2010 OWA and use a SAN cert. Then they will go to the 2010 CAS first even if they use the 2003 URLs. The Deployment Assistant is helpful if you havent seen it already: http://technet.microsoft.com/en-us/exdeploy2010/default.aspx#Home