Q. How do I create a routing group connector to transport messages between my first Exchange Server 2007 server and my existing Exchange Server 2003 environment?

A. When installing an Exchange 2007 server into an Exchange 2003 or Exchange 2000 Server environment, you will be prompted to select an Exchange 2003 or Exchange 2000 bridgehead server. A Hub Transport server uses the routing group connector to transport messages between the Exchange 2007 server and the Exchange 2003 or Exchange 2000 bridgehead servers.

Routing groups aren’t used in exclusive Exchange 2007 environments. Active Directory sites and site link costs are used to transport messages. The routing group connector is only used by the Exchange 2007 environment to enable message flow to and from the legacy Exchange servers. It is best to add additional source- and target-servers to this automatically created routing group connector for redundancy and load balancing.

If your email topology didn’t change when introducing the Exchange 2007 server, you don’t have to manually add another routing group connector. The connector should automatically create a connector during setup, and it should route messages between the legacy and Exchange 2007 servers. All Exchange 2007 servers are automatically placed in a single routing group—Exchange Routing Group (DWBGZMFD01QNBJR). This routing group is connected to the legacy environment through the automatically generated routing group connector. Don’t rename this routing group or remove the Exchange 2007 servers from it.

I have seen instances where the routing group connector was not automatically created. If this happens, check the Exchange setup logs and event logs for errors. You may need to manually add a connector using the PowerShell command below. You can add multiple source and target servers by specifying multiple FQDN server names separated by a comma, e.g. 'SourceTransportServers '',''.

New-RoutingGroupConnector -Name 'Exchange 2007 RGC' -SourceTransportServers '' -TargetTransportServers 'FQDN of Exchange 2003 Bridgehead Server' -Cost 100 -Bidirectional $true -PublicFolderReferralsEnabled $true

The command Get-RoutingGroupConnector can verify the existence of the routing group connector. You won't be able to see it from the GUI console.