Has anyone experience with exposing the web access (OWA) of an Exchange 2010 server through a Cisco ASA (my goal is to something like a DMZ)? If so could you give me some advice? I know that Exchange doesn't support DMZ and that MS recommends using TMG. Still, I'd like to know if someone has managed this (I've tried and wasn't very successsful so far). Or would it be better to ditch (read: sell) the ASA and use a TMG server instead? We're completely on Windows Server 2008 R2 and some remaining 2003 server running mostly as file servers. We don't use the VPN features much at the moment but plan on doing that in the future, but OWA should be there if VPN is not possible from outside.

Thank you very much!