We have a mailbox with the primary SMTP address of firstname.lastname@example.org. (Display name in Active Directory is Test Mailbox.) The mailbox also has several other aliases, such as email@example.com and firstname.lastname@example.org. The domains are not always the same; we host several different domain names. Prior to removing the IMS, when a user received an e-mail from email@example.com the "from" line would still have firstname.lastname@example.org as the sender. Now when the user receives the e-mail, it states Test Mailbox in the "from" line.
Why did this change when we removed the IMS and routed messages through the SMTP connector?
1. Launch Exchange System Manager (ESM).
2. Navigate to the Global Settings container, which should be at the top of the left-hand pane in ESM.
3. Highlight "Internet Message Format" and view the properties for "default" listed in the right panel of ESM.
4. Click on the Advanced tab.
5. Uncheck "Preserve sender's display name on message."
Your messages should now be getting to your Internet recipients with just the SMTP address appearing in the "From" field. If, by chance, you are also observing the same behavior that I just described on messages sent in-bound to your organization, then there's a chance that you were experiencing what is described in Microsoft Knowledge Base Article 242301 "XCLN: Messages Received from Internet Display SMTP Address on the To and Cc Lines." That scenario only applies when users are co-located on the same Exchange 5.5 server as your Internet Mail Service (IMS). In this case, the P2 header information is not resolved as described in the article. If that was the case, you can achieve similar functionality by following the instructions in Microsoft Knowledge Base Article 288635 "XIMS: ResolveP2 Functionality in Exchange 2000 Server."
This was first published in October 2004