XFOR: New IMS Routing Functionality in Exchange Server 5.0 SP2

In Microsoft Exchange Server version 5.0, the Internet Mail Service has the added ability to reroute Internet mail. To configure this feature, you have to specify any domain(s) that will be handled by Exchange Server. When you specify a domain in the Routing tab of the Internet Mail Service, a subdomain match is implied.

In Exchange Server 5.0 Service Pack 2 (SP2), you now have the ability to specify an exact domain match in the routing list.

In Exchange Server 5.0 and Exchange Server 5.0 Service Pack 1 (SP1), if you specify

   ms.com     host1.ms.com
				

in the routing list, then this implies that you also want other subdomains (for example, sales.ms.com) to be rerouted to host1.ms.com.

The rerouting capabilities have been modified in Exchange Server 5.0 SP2 to allow you to specify an exact domain match instead of always doing subdomain matches.

To do this you must add a pound sign (#) in front of any domains you want exact matches for. A domain with a pound sign prefix indicates that domain must exactly match the destination domain (the domain in user@domain) to trigger the associated routing action.

For example, take the following list:

   Sent To     Route To
   =======     ========
   ms.com      host1.ms.com
   #ms.com     <inbound>
   x.ms.com    <inbound>
				

Mail should be routed as follows:

   User@ms.com ===> routed inbound
   User@sales.ms.com ===> routed to host1.ms.com
   User@x.ms.com ===> routed inbound
   User@pms.com ===> routed to pms.com
   User@abc.x.ms.com ===> routed inbound
				

The matches are done in the following order:

1.	Check for a match in the exact match list.
2.	Check for best match among the non-exact match list.
3.	If no match, reroute to the destination domain.

This feature is included in the latest U.S. Service Pack for Microsoft Exchange Server version 5.0. For information on obtaining the service pack, query on the following word in the Microsoft Knowledge Base (without the spaces):