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Q159192: XCON: MTA Shows High CPU Usage and Messages Not Delivered

Article: Q159192
Product(s): Microsoft Exchange
Version(s): winnt:4.0
Operating System(s): 
Keyword(s): 
Last Modified: 09-APR-1999

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The information in this article applies to:

- Microsoft Exchange Server, version 4.0 
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SYMPTOMS
========

The Microsoft Exchange message transfer agent (MTA) shows very high CPU usage
and messages do not move from their queues. This high CPU usage (near 100
percent) persists for extended periods of time and is viewable using Performance
Monitor. The computer running Windows NT Server and Microsoft Exchange Server
may perform slowly.

To observe the MTA CPU Usage using Performance Monitor:

1. Start Performance Monitor

2. On the Edit menu, click Add to Chart.

3. For the Object, select Process.

4. For the Instance, select emsmta.

5. For the Counter, select "% Processor Time."

6. Click Add.

You should view the CPU usage over time to see if it persists at a high value
(close to 100 percent). It can be quite normal for the MTA to run with high CPU
usage, but it should not persist indefinitely. (You should analyze your systems
using this technique to establish a baseline for comparison purposes.)

CAUSE
=====

In rare cases of message corruption, the Microsoft MTA can incur high CPU
overhead while processing messages with Distribution Lists. The most likely
cause of this corruption is improper shutdown of the computer running Microsoft
Exchange Server.

STATUS
======

Microsoft has confirmed this to be a problem in Microsoft Exchange version 4.0.
This problem was corrected in the latest Microsoft Exchange 4.0 U.S. Service
Pack. For information on obtaining the service pack, query on the following word
in the Microsoft Knowledge Base (without the spaces):

  S E R V P A C K


Additional query words: hung cpu bound pegging 100% percent

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Keywords          :  
Technology        : kbExchangeSearch kbExchange400 kbZNotKeyword2
Version           : winnt:4.0
Issue type        : kbbug
Solution Type     : kbfix

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