PLANNING
Network mail routing occurs across a mix of hub-and-spoke and peer-to-peer connections.
In a hub-and-spoke topology, mail traffic passes between a central hub server and multiple spoke servers; no mail is exchanged directly among the spokes. A hub-and-spoke topology is suited to handling a high volume of mail across a large organization. In a peer-to-peer topology, on the other hand, every server connects to every other server.
Note: You cannot use a wildcard character (*) to represent part of the source server's name in a Connection document that is used to define routing from all spoke servers in a domain to a central hub server or server cluster.
Related concepts Planning server-to-server connections Planning a mail routing topology Replication and server topology