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Q173343: XFOR: Slow Processing of Internet Messages with MIME Bodyparts

Article: Q173343
Product(s): Microsoft Exchange
Version(s): winnt:5.0
Operating System(s): 
Keyword(s): kbusage
Last Modified: 07-JAN-2000

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The information in this article applies to:

- Microsoft Exchange Server, version 5.0 
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SYMPTOMS
========


When you receive messages from the Internet with nested MIME (Multipurpose
Internet Mail Extensions) bodyparts, the conversion process for the MIME
bodyparts may cause the slow delivery of these messages. As the messages are
delivered, the server will require a large amount of system resources,
especially memory. If a large number of these messages are received at the same
time, the system may report it is running low on virtual memory.

CAUSE
=====

MIME bodyparts within a message item can be nested. If the nesting level is
high, the conversion process requires more and more resources to decode the
entire message. A single message with a MIME bodypart nested to 700 levels can
take up to 10 minutes to process.

STATUS
======

Microsoft has confirmed this to be a problem in Exchange Server version 5.0.
This problem has been corrected in the latest U.S. Service Pack for Microsoft
Exchange Server version 5.0. For information on obtaining the Service Pack,
query on the following word in the Microsoft Knowledge Base:

  " SERVPACK " (without the quotation marks)


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

Because it is unlikely that valid messages will be nested to much more than 30
levels, the Microsoft Exchange information store should not try to process
messages beyond this point. A new registry key has been added in the fix
referred to in the STATUS section above that limits the amount of nesting the
information store will process. The registry switch is at:

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\MSExchangeIs\Parame
tersSystem\InternetContent\LimitNestingLevels

If this entry is missing, a default of 30 nested MIME bodyparts will be processed
per message. Specifying a DWORD value will prevent messages from being processed
with nested bodyparts above that level. A value of zero will prevent all
messages containing MIME bodyparts from being processed.

Additional query words: 5.00 SP1 IMS IMC CONVERSION

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Keywords          : kbusage 
Technology        : kbExchangeSearch kbExchange500 kbZNotKeyword2
Version           : winnt:5.0
Solution Type     : kbfix

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