HiLet's say I have an Exchange 2003 org with 3 Administrative groups. Each Admin group is also a Routing Group: USA, Canada, Europe.Each RG contains two mailbox servers and a bridgehead server. A user in USA, domain\User1, sends an email to a user in Europe, domain\User2.I know the AD attributes for each user contains information on homeMDB (their Mailbox Store) and homeMTA (their home Exchange server), how I can't seen anywhere that holds information on what Routing Group the home Exchange server belongs to? I've checked the AD properties of our Exchange servers, and don't see this attribute listed?So does anyone know how Exchange actually routes mail between Routing Groups?...and how does this change in Exchange 2007, since I don't see Exchange servers having attributes for AD site either?Thanks for any explanation.

Hi, For Exchange 2003 Server, the Exchange AD object has msExchHomeRoutingGroup attribute indicated which Routing Group the server belongs. For Exchange 2007 Server, the Exchange AD object has msExchServerSite attribute indicated which AD Site the server belongs. ~~~~~~~~~~~~~~~~Mike Shen TechNet Subscriber Support in forum If you have any feedback on our support, please contact tngfb @ microsoft.com ~~~~~~~~~~~~~~~~