Article ID: 327260 - View products that this article applies to.
This article was previously published under Q327260
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Important This article contains information about how to modify the registry. Make sure to back up the registry before you modify it. Make sure that you know how to restore the registry if a problem occurs. For more information about how to back up, restore, and modify the registry, click the following article number to view the article in the Microsoft Knowledge Base:
(http://support.microsoft.com/kb/256986/ )Description of the Microsoft Windows registry
When you run Exchange Server 5.5, the message transfer agent (MTA) may slow down or stall. Messages may back up in the private information store. If you try to run Microsoft Exchange Performance Optimizer (Perfwiz.exe), the overall performance of Exchange Server may slow down.
This issue occurs because Performance Optimizer does not allocate sufficient information store threads to increase the routing capacity of the MTA. Performance Optimizer also resets any changes that you make. Make sure that you make any changes on all servers in the environment.
To resolve this issue, use one of the following methods.
Run Performance Optimizer in verbose mode to modify thread counts
Modify the registryWarning Serious problems might occur if you modify the registry incorrectly by using Registry Editor or by using another method. These problems might require that you reinstall your operating system. Microsoft cannot guarantee that these problems can be solved. Modify the registry at your own risk.
To resolve this behavior, create or change the following values in the Windows NT registry:
Performance Monitor in verbose mode stops all services and offers options that are not available in normal mode. You do not have to analyze hard disks or move files. You can use this procedure to change some resource (thread) settings from the defaults.
To view the current settings for this server without stopping services, type perfwiz -r (at a command prompt). You can also use the Perfopt.log file in the Winnt\System32 folder to view any changes that Performance Optimizer makes to the system.
For more information about MTA fanout, messages in the information store, and improving MTA network performance, click the following article numbers to view the articles in the Microsoft Knowledge Base:
(http://support.microsoft.com/kb/265186/ )MTA fanout slows on multiprocessor servers, and messages back up in information store
(http://support.microsoft.com/kb/176046/ )Routing issues with Microsoft Exchange Server, version 5.0
(http://support.microsoft.com/kb/159184/ )MTA does not deliver messages with high directory service activity
(http://support.microsoft.com/kb/234280/ )How to increase the ability of the MTA to pass mail over slow network connections
(http://support.microsoft.com/kb/234702/ )MTA queue to information store processing slowly
(http://support.microsoft.com/kb/247782/ )Mail transfer slow across connectors, event IDs 3120 and 9316 appear
Note that if you change the public and private send and deliver threads as described in Knowledge Base article 234702, you must also check the concurrent X.400 application programming interface (XAPI) sessions to make sure that the value is set adequately. Otherwise, you may experience new performance issues and may receive an Event ID 3120 error message from the MTA.
Article ID: 327260 - Last Review: October 26, 2013 - Revision: 8.1