I am currently planning a Exchange 2007 to 2010 migration for a client that needs to have full redundancy in the design. Currently they run a single Exchange 2007 server with all the roles, and 2 spam filters. My question is do i realy need the Edge Transport role in the new 2010 environment? And were to place the HT role?
I am currently planning 2 Mailbox servers running DAG and HT, 2 CAS servers in a NLB cluster, using the 2 inbound spamfliters to act as the ET's.