Registrations are now open. Join us today!
There is still a lot of work to do on the wiki yet! More information about editing can be found here.
Already have an account?

Microsoft KB Archive/169319

From BetaArchive Wiki
Knowledge Base

XFOR: Performance Tuning the PCMTA

Article ID: 169319

Article Last Modified on 10/28/2006


  • Microsoft Exchange Server 4.0 Standard Edition
  • Microsoft Exchange Server 5.0 Standard Edition

This article was previously published under Q169319

IMPORTANT: This article contains information about editing the registry. Before you edit the registry, make sure you understand how to restore it if a problem occurs. For information about how to do this, view the "Restoring the Registry" Help topic in Regedit.exe or the "Restoring a Registry Key" Help topic in Regedt32.exe.


Administrators of Microsoft Exchange Server versions 4.0 and 5.0 have the ability to tune the Microsoft Mail Connector (AppleTalk) MTA (PCMTA); the component that facilitates communication between Exchange and Microsoft Mail for PC Networks.


Tuning takes the form of three registry settings associated with the PCMTA service created by the installer of the Microsoft Mail Connector. That name will be declared on the connector's MTA tab. In this article, the service will be called Legacy Mail Connector.

WARNING: Using Registry Editor incorrectly can cause serious problems that may require you to reinstall your operating system. Microsoft cannot guarantee that problems resulting from the incorrect use of Registry Editor can be solved. Use Registry Editor at your own risk.

For information about how to edit the registry, view the "Changing Keys And Values" Help topic in Registry Editor (Regedit.exe) or the "Add and Delete Information in the Registry" and "Edit Registry Data" Help topics in Regedt32.exe. Note that you should back up the registry before you edit it.

To tune the connector, perform the following steps:

  1. Start Registry Editor (Regedt32.exe), and go to the following subkey:

          \Services\Legacy Mail Connector\Parameters

    NOTE: The above registry key is one path; it has been wrapped for readability.

  2. From the Edit menu, click Add Value and add the following information:

       QueueInqueueLimit REG_SZ (value not to exceed 200)
       QueueLanMailbagLimit REG_SZ (value not to exceed 200)
       QueueLanPoLimit REG_SZ (value not to exceed 200)

    NOTE: Microsoft has not seen significant improvement when any of these values exceeds 200. Microsoft recommends a maximum setting of 200.

  3. Quit Registry Editor and restart your computer.

By default, these values are coded into the service and set to 50. Adding these values overrides the defaults. Administrators running the PCMTA in a large legacy mail environment can take advantage of these settings and increase throughput.

Additional query words: XFOR, performance, tune, PCMTA, MSMI

Keywords: KB169319