Microsoft Exchange 2000 Server functions as though servers in the same routing
group are on a network with full-time, reliable
connections, and Exchange does not attempt to make network
communications more efficient between the servers. You can create
the most efficient messaging system by grouping servers with
full-time, reliable connections into a routing group, and then by
adding connectors to link the routing group to other servers with
which the connection is intermittent or unreliable.