Microsoft KB Archive/238189

= XCON: Duplicate Messages Delivered After MTA Restart =

Article ID: 238189

Article Last Modified on 10/28/2006

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APPLIES TO


 * Microsoft Exchange Server 5.5 Service Pack 2

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This article was previously published under Q238189



SYMPTOMS
When the message transfer agent (MTA) is under heavy stress, Db*.dat files are sometimes not cleaned up properly. In some cases, these files are also not marked as "used." When the MTA is restarted, the queues are rebuilt based on all of the Db*.dat files that are "not used" in the Mtadata folder. Because these files have not been cleaned up or marked as delivered, restarting the MTA in this state produces duplicate mail to the local store.

In addition, when the MTA is in this state it cannot be shut down cleanly. Consequently, either killing the MTA or hard-booting the server are the only options to bring it down.



CAUSE
Viewing the Performance Monitor counter MSExchangeMTA, with the instance Work Queue Length, reveals a steady increase but no message backlog in any other queue. This is a result of the Db*.dat files not being marked as "used."



RESOLUTION
A supported fix is now available from Microsoft, but it is only intended to correct the problem that is described in this article. Apply it only to computers that are experiencing this specific problem. This fix may receive additional testing. Therefore, if you are not severely affected by this problem, Microsoft recommends that you wait for the next Microsoft Exchange Server version 5.5 service pack that contains this hotfix.

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 about support costs, visit the following Microsoft Web site:

http://support.microsoft.com/default.aspx?scid=fh;EN-US;CNTACTMS

NOTE: In special cases, charges that are ordinarily incurred for support calls may be canceled if a Microsoft Support Professional determines that a specific update will resolve your problem. The typical support costs will apply to additional support questions and issues that do not qualify for the specific update in question.

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

Component: Message Transfer Agent



STATUS
Microsoft has confirmed that this is a problem in Microsoft Exchange Serverversion 5.5.

Keywords: kbbug kbfix KB238189

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