I plan to upgrade my Exchange 2003 to 2010. I have only single Exchange 2003 server. When I read through the Exchange 2010 documentation, it mentions that CAS, Hub Transport, Mailbox roles can be on the same computer, and Edge Transport role must be outside the domain.
Q#1. Is Edge Transport role required?
Q#2. If Edge Transport role is skipped, what features/advantages are lost?
Q#3. Does my MX record point to Edge Transport server or CAS server?