Microsoft KB Archive/301401

= XFOR: SMTP Tries to Deliver Messages to External Exchange 2000 Servers with Names That Are Not FQDNs Until an Expiration Time-Out Occurs =

Article ID: 301401

Article Last Modified on 2/20/2007

-

APPLIES TO


 * Microsoft Exchange 2000 Server Standard Edition

-



This article was previously published under Q301401





SYMPTOMS
Mail may form a queue to remote Exchange computers (outside the organization) until an expiration time-out occurs. A non-delivery report (NDR) may be generated that is similar to:

test@microsoft.com on 6/11/2001 12:39 PM

Could not deliver the message in the time limit specified.

Please retry or contact your administrator.

< ex2000.dotnet.net #4.4.7>

This problem does not occur with computers that are not Exchange 2000 servers. This problem also does not occur with Exchange 2000 servers that return a fully qualified domain name (FQDN) in the initial response.



CAUSE
Exchange 2000 uses an ESMTP extension that is not standard for authentication. In accordance with the relevant Request for Comments (RFC) document, this non-standard extension is prefaced with X-.

This extension (X-EXPS) is implemented as a protocol sink in the Microsoft Windows 2000 Simple Mail Transfer Protocol (SMTP) service. This protocol sink uses the initial response from the server to determine whether a computer is local to the Exchange organization or is outside the Exchange organization.

The name that the server reports (whether it is a FQDN or not) is passed to Windows 2000 application programming interface (API) functions to determine the location of the message. An error is returned from this function for names that are not FQDNs.

Exchange 2000 notes the error and determines that it can try to deliver the message again. Therefore, the message stays in the queue, and Exchange 2000 continuously tries to deliver the message until the time-out occurs. The message eventually generates a non-delivery report (NDR) that is similar to the NDR in the &quot;Symptoms&quot; section of this article.



RESOLUTION
To resolve this problem, obtain the latest service pack for Microsoft Exchange 2000 Server. For additional information, click the following article number to view the article in the Microsoft Knowledge Base:

301378 XGEN: How to Obtain the Latest Exchange 2000 Server Service Pack

The English version of this fix should have the following file attributes or later:

Component: SMTP

NOTE: Because of file dependencies, this update requires Microsoft Exchange Server 2000 Service Pack 1.



STATUS
Microsoft has confirmed that this is a problem in Microsoft Exchange 2000 Server. This problem was first corrected in Microsoft Exchange 2000 Server Service Pack 2.



MORE INFORMATION
This fix changes this behavior. After the fix is applied, computers that cause the Windows 2000 API function to return an error are considered remote (not local). Therefore, those computers are not authenticated, and the message is sent.

Inside the Exchange organization, virtual servers with an FQDN that is not valid or a name that is not an FQDN may not be able to receive mail correctly. This is the case both before and after you apply this fix.

If you are an administrator, make sure that all of the inbound virtual servers have correct FQDNs.

Keywords: kbbug kbexchange2000presp2fix kbexchange2000sp2fix kbfix KB301401

-

[mailto:TECHNET@MICROSOFT.COM Send feedback to Microsoft]

© Microsoft Corporation. All rights reserved.