⟩ Can the Exchange 2007 server roles be deployed and configured on the same physical hardware?
Because Exchange 2007 is role-based, you can deploy all Exchange Server 2007 server roles, except the Edge Transport server role on a single physical server. If you are clustering, you cannot deploy the Mailbox server role on the same server as the Client Access, Unified Messaging, Hub Transport, or Edge Transport server roles. When the server roles are installed on the same or shared hardware, they function as separate entities.