XCON: X.400 MTA Logs "Loop Detected" Error Message When Receiving a Message from Exchange Server

ID: Q232586

The information in this article applies to:

Microsoft Exchange Server, version 5.5

SYMPTOMS

In some cases, a third-party X.400 message transfer agent (MTA) may log an error message similar to "Loop detected" when it receives a message from Exchange Server. The originator of the message will receive a non-delivery report (NDR).

This behavior only occurs under very specific circumstances:

A message is sent from Exchange Server using the X.400 Connector. The recipients in the message are taken from the user's Personal Address Book (PAB) or are one-off addresses. At the same time, custom recipients exist for these addresses in the Exchange Server global address list.

The message may contain multiple trace records in the X.400 P1 message header, which are marked as "rerouted." This may cause the receiving MTA to think there is a message loop.

The number of trace records in the P1 message header depends on the number of recipients addressed. For example, if the message was sent to three recipients, there will be three trace records.

RESOLUTION

A supported fix that corrects this problem is now available from Microsoft, but it has not been fully regression tested and should be applied only to systems experiencing this specific problem. If you are not severely affected by this specific problem, Microsoft recommends that you wait for the next Microsoft Exchange Server version 5.5 service pack that contains this fix.

To resolve this problem immediately, contact Microsoft Product Support Services to obtain the fix. For a complete list of Microsoft Product Support Services phone numbers and information on support costs, please go to the following address on the World Wide Web:

http://www.microsoft.com/support/supportnet/overview/overview.asp

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

Component: Message Transfer Agent (MTA)

File name	Version
Dbserver.sch	N/A
Dcprods.cat	N/A
Ems_rid.dll	5.5.2621.0
Emsmta.exe	5.5.2621.0
Info4log.cfg	N/A
Infoblog.cfg	N/A
Infodlog.cfg	N/A
Infollog.cfg	N/A
Infoplog.cfg	N/A
Infotlog.cfg	N/A
Mtacheck.exe	5.5.2621.0
Mtamsg.dll	5.5.2621.0
P2.xv2	N/A
X400om.dll	5.5.2621.0
X400omv1.dll	5.5.2621.0

NOTE: If this product was already installed on your computer when you purchased it from the Original Equipment Manufacturer (OEM) and you need this fix, please call the Pay Per Incident number listed on the above Web site. If you contact Microsoft to obtain this fix, and if it is determined that you only require the fix you requested, no fee will be charged. However, if you request additional technical support, and if your no-charge technical support period has expired, or if you are not eligible for standard no-charge technical support, you may be charged a non-refundable fee.

For more information about eligibility for no-charge technical support, see the following article in the Microsoft Knowledge Base:

Q154871 Determining If You Are Eligible for No-Charge Technical Support

STATUS

Microsoft has confirmed this to be a problem in Microsoft Exchange Server version 5.5.

Additional query words: word-wrap truncated deleted


Keywords          : 
Version           : winnt:5.5
Platform          : winnt 
Issue type        : kbbug

Last Reviewed: June 28, 1999