Outlook Anywhere redirect not working (Exchange 2013 to Exchange 2007)

Hi guys,

At this moment, I have Exchange 2013 and Exchange 2007 coexisting.

I am publishing Exchange 2013 through UAG and Exchange 2007 with ISA. In 2013 everything is fine. In Exchange 2007, I have set up a legacy namespace, the name is also included in the certs, external DNS and all External URL's on this side.

Apart from having to log into various OWA interfaces for Exchange 2007 users that is pretty much fine too apart from Outlook Anywhere. While it works well for a 2013 user, a 2007 user has to login many times and then it fails.

I did some testing with ExRCA with a 2007 user, and get the error: "A Web exception occurred because an HTTP 302 - Redirect response"

Can anyone shed light on my problem?

Thanks!