http://technet.microsoft.com/zh-tw/magazine/ff626260.aspx Q: I’m planning to upgrade our environment from Microsoft Exchange 2007 to Exchange 2010. This im plementation has to be fully redundant on all levels.Because our organization has about 3,000 users, I plan to install Exchange on two machines initially. Each will have the Hub Transport (HT), Client Access Server (CAS) and Mailbox (MB) server roles. Both will also be members of a Database Availability Group (DAG), so the servers will replicate databases between themselves . From our experience with the current Exchange environment, I know that if the HT and MB roles are on the same machine, the Microsoft Exchange Mail Submission service always prefers the local HT server. It doesn’t use other HT servers in the Active Directory site in a round robin fashion, as do MB servers that don’t have the HT server role. If this is the same in Exchange 2010, we have an issue. Keeping the transport dumpster on a DAG member doesn...