I am working on an Exchange 2010 implementation for my organization. I have a question regarding email routing. With Exchange 2003 all roles where combined on one box so obviously my MX record for my organization would point to my Exchange 2003 server. In Exchange 2010, with the roles being segmented which server should my MX record point to. I plan on running individual servers for CAS, HUB, and Mailbox. Would my MX record need to point my HUB server or my MB server ??/ Any insight would be greatly appreciated.