DOCUMENT:Q254812  10-NOV-2000  [exchange]
TITLE   :XADM: MTA Backlogs to Private and Public Information Store
PRODUCT :Microsoft Exchange
PROD/VER:winnt:5.5
OPER/SYS:
KEYWORDS:exc55 kbExchange550preSP4fix kbExchange550sp4Fix

======================================================================
-------------------------------------------------------------------------------
The information in this article applies to:

 - Microsoft Exchange Server, version 5.5 
-------------------------------------------------------------------------------


SYMPTOMS
========

Message transfer agent (MTA) queues to the private or public information stores
may increase during the day. The MTA does not stop delivering e-mail, but it is
sluggish and only delivers approximately three to five messages each minute.

This may happen randomly on servers throughout the organization. Performance
improves when fewer users work on the server, usually later in the afternoon.
The MTA queue clears within an hour of the close of business. The following day
the affected server behaves normally. When the MTA queues are large, users may
experience a delay in e-mail delivery (incoming e-mail messages), but outgoing
e-mail messages are not affected.

CAUSE
=====

This issue can occur because of a space tree issue. Exchange Server tries to
coalesce a page that is being freed with one of the neighbors of the page and
navigates thousands of empty btree pages when it does so.

RESOLUTION
==========

To resolve this problem, obtain the latest service pack for Exchange Server 5.5.
For additional information, please see the following article in the Microsoft
Knowledge Base:

   Q191014 XGEN: How to Obtain the latest Exchange Server 5.5 Service Pack


WORKAROUND
==========

To work around this issue:

1. Restart the server.

2. Perform an offline defragmentation.

3. Add more random access memory (RAM).

STATUS
======

Microsoft has confirmed this to be a problem in Microsoft Exchange Server
version 5.5. This problem was first corrected in Exchange Server 5.5 Service
Pack 4.

MORE INFORMATION
================

This issue is a variation of a space tree issue. For additional information,
click the article number below to view the article in the Microsoft Knowledge
Base:

   Q230691 XADM: Space Tree Fragmentation in Exchange Database Engine Can
   Degrade Server Performance

   Q234702 XGEN: MTA Queue to Information Store Processing Slowly


Additional query words:

======================================================================
Keywords          : exc55 kbExchange550preSP4fix kbExchange550sp4Fix 
Component         : JET
Technology        : kbExchangeSearch kbExchange550 kbZNotKeyword2
Version           : winnt:5.5
Issue type        : kbbug
Solution Type     : kbfix

=============================================================================

THE INFORMATION PROVIDED IN THE MICROSOFT KNOWLEDGE BASE IS
PROVIDED "AS IS" WITHOUT WARRANTY OF ANY KIND.  MICROSOFT DISCLAIMS
ALL WARRANTIES, EITHER EXPRESS OR IMPLIED, INCLUDING THE WARRANTIES
OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.  IN NO
EVENT SHALL MICROSOFT CORPORATION OR ITS SUPPLIERS BE LIABLE FOR
ANY DAMAGES WHATSOEVER INCLUDING DIRECT, INDIRECT, INCIDENTAL,
CONSEQUENTIAL, LOSS OF BUSINESS PROFITS OR SPECIAL DAMAGES, EVEN IF
MICROSOFT CORPORATION OR ITS SUPPLIERS HAVE BEEN ADVISED OF THE
POSSIBILITY OF SUCH DAMAGES.  SOME STATES DO NOT ALLOW THE EXCLUSION
OR LIMITATION OF LIABILITY FOR CONSEQUENTIAL OR INCIDENTAL DAMAGES
SO THE FOREGOING LIMITATION MAY NOT APPLY.

Copyright Microsoft Corporation 2000.