XIMS: How to Force SMTP Messages Through the Information Store

This article explains how to reroute messages through the Microsoft Exchange Server information store before sending to the Internet. Enabling the rerouting adds some advantage because the rerouted messages have more readable addresses. These messages are re-routed through the information store by using the Registry Editor (Regedt32.exe) to set the following registry value to 1:

WARNING: If you use Registry Editor incorrectly, you may cause serious problems that may require you to reinstall your operating system. Microsoft cannot guarantee that you can solve problems that result from using Registry Editor incorrectly. Use Registry Editor at your own risk.

When this registry value is set to 1, it internally enables two parameters required for this option to work, if they aren't already enabled, namely the P2Resolve and AddressRewrite parameters.

If you enable rerouting of the Internet Mail Service object, then outbound messages are rerouted through the information store instead of being re-sent or "bounced" as normal. The Rerouting tab is located on the Internet Mail Server Routing property page, in the Configuration container.

Enabling rerouting adds some advantage because the rerouted message's P1 and P2 From field, and P2 recipients are replaced with any locally matched custom recipient's reply address. Addresses without matching custom recipients are not altered. P1 recipients continue to be rewritten in accordance with the routing table.