I am working on transitioning from Exchange 2003 to Exchange 2010. In looking through most of the walkthroughs it seems that one of the first things I need to do is to setup the client access server and reroute my owa. Is there anyway for me to do testing without changing my current owa to legacy.whatever.com\owa until I'm ready. I was hoping to test it internally by IP or internal address and leave the external one alone. Do changing the OWA and creating certificates for this new site have to be the first step.