Topic Last Modified: 2005-11-18

The Microsoft® Exchange Server Analyzer Tool reads the following registry entry to determine its current value:

HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\MSExchangeMTA\Parameters\RTS threads

If the Exchange Server Analyzer finds the value for RTS threads present and greater than 0 but set to anything other than 1 or 3, a non-default configuration message is displayed.

The RTS threads value is the number of platform threads that handle the Reliable Transfer Service Element (RTSE) level of the Open Systems Interconnection (OSI) stack. RTS threads are responsible for putting data in the queues. You should adjust the RTS threads registry value from the default of 1 to a value of 3 if this message transfer agent (MTA) communicates with multiple Exchange Server version 5.5 computers either within a site or between sites.

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

To optimize the RTS threads registry value

  1. Open a registry editor, such as Regedit.exe or Regedt32.exe.

  2. Navigate to: HKLM\System\CurrentControlSet\Services\MSExchangeMTA\Parameters

  3. In the right pane, locate and double-click the RTS threads value.

  4. In the Value data field, enter the appropriate value (1 or 3) and click OK.

  5. Exit the registry editor and restart the Microsoft Exchange MTA Stacks service for the change to take effect.

Before you edit the registry, and for information about how to edit the registry, see the Microsoft Knowledge Base article 256986, "Description of the Microsoft Windows Registry" (