XCCC: The "From" Field Is Not Populated in Posts to Public Folders from a Separate Forest

If a user in one (trusted) Active Directory forest posts an item to public folders in another Active Directory forest, useful From field and e-mail address information may not be stored with the post to the public folders.

This issue occurs because the only information that is available about such a user is the user's Microsoft Windows NT Security Identifier (SID). By definition, that SID does not match the objectSid attribute of any user object in the forest where the public folders are located.

To resolve this issue, an administrator can add the ResolveForeignUsers registry key on servers in the forest where the public folders are located. If the ResolveForeignUsers registry key is set, Exchange 2000 attempts to find a matching Contact object in the forest where the public folders are located. A matching Contact has an alias (mail nickname) that matches the "user" portion of the Security Accounts Manager (SAM) account name. If Exchange 2000 finds a matching Contact object, the display name and e-mail address of that Contact are used when the user posts an item to a public folder. This change enables users from other forests to fully participate in the type of collaboration that public folders make possible.

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.

To add the ResolveForeignUsers registry key:

1. Start Registry Editor (Regedt32.exe).
2. Locate and click the following key in the registry:
   HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\MSExchangeWEB\OWA
3. On the Edit menu, click Add Value, and then add the following registry value:
   Value name: ResolveForeignUsers
   Data type: REG_DWORD
   Radix: Decimal
   Value data: 1
4. Quit Registry Editor.

This ResolveForeignUsers key is not present by default. You must add the ResolveForeignUsers key on each server where you want to enable this feature. After you implement this registry value, posts from users in the other forests contain domain\user_name in the From field as expected.

If Exchange 2000 does not find a Contact in the local Active Directory, the post display name is set to "domain\user." The e-mail address is not set.