Article ID: 288635
This article was previously published under Q288635
This article has been archived. It is offered "as is" and will no longer be updated.
IMPORTANT: This article contains information about modifying the registry. Before you modify the registry, make sure to back it up and make sure that you understand how to restore the registry if a problem occurs. For information about how to back up, restore, and edit the registry, click the following article number to view the article in the Microsoft Knowledge Base:
(https://support.microsoft.com/kb/256986/EN-US/ )Description of the Microsoft Windows Registry
After Exchange 2000 Server Service Pack 1 (SP1) is installed, Exchange 2000 Server administrators can enable the ResolveP2 functionality. For additional information about ResolveP2 functionality, click the article numbers below to view the articles in the Microsoft Knowledge Base:
(https://support.microsoft.com/kb/166163/EN-US/ )XCLN: Err Msg: No Transport Provider Was Available
174755NOTE: The registry key definitions have changed between Exchange Server 5.5 and Exchange 2000; the following instructions only apply to Exchange 2000.
(https://support.microsoft.com/kb/174755/EN-US/ )XFOR: ResolveP2 Registry Setting Expanded in Exchange 5.5
The ResolveP2 registry setting contains information that Exchange 2000 can use to "resolve" specified addresses in a mail message body (referred to as "P2"), if those users exist in the Exchange 2000 directory. A resolved address is displayed as follows when the mail message is received by a mail client, such as Microsoft Outlook:
From: First_nameLast_nameAn unresolved address is displayed as follows:
From: First_nameLast_name [email@example.com]If you double-click a resolved address in the client, the Exchange 2000 directory information is displayed. An unresolved address simply displays the Simple Mail Transport Protocol (SMTP) address. Because this is the resolution behavior for internal addresses, an external resolved address can lead a mail user to believe that mail originated from within the local domain or organization. If you enable the ResolveP2 setting, educated users can tell the difference between internal and external mail.
Set the ResolveP2 key on the server that receives mail from the Internet. If you are upgrading from Exchange Server 5.5, you still need to use the following steps because the Exchange Server 5.5 keys are not used by Exchange 2000.
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 set the ResolveP2 key: