I need a bit of help with ISA 2006 and OWA. I’ve setup access rules and listeners to facilitate OWA access to my Exchange server via ISA. The rules seem to work fine and any internal client – not using proxy can access the OWA forms, but internal clients – using proxy can’t. They get Error Code 502 proxy server denied the specified URL (12202) even though the listener is configured to listen on both networks. I’m not using split DNS as my ISP is handling external resolution. My internal DNS points owa.domain.co.uk to the ISA server itself. The clients using proxy trip up on the default rule.
Any ideas as to why internal client using proxy fail but internal clients not using proxy don’t and how to sort it out?