MTA Concurrent connections to X.400 gateways parameter is non-default
[This topic is intended to address a specific issue called out by the Exchange Server Analyzer Tool. You should apply it only to systems that have had the Exchange Server Analyzer Tool run against them and are experiencing that specific issue. The Exchange Server Analyzer Tool, available as a free download, remotely collects configuration data from each server in the topology and automatically analyzes the data. The resulting report details important configuration issues, potential problems, and nondefault product settings. By following these recommendations, you can achieve better performance, scalability, reliability, and uptime. For more information about the tool or to download the latest versions, see "Microsoft Exchange Analyzers" at http://go.microsoft.com/fwlink/?linkid=34707.]
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\Concurrent connections to X.400 gateways
If the Exchange Server Analyzer finds the value for Concurrent connections to X.400 gateways present and set to anything other than 6, a non-default configuration message is displayed.
The Concurrent connections to X.400 gateways registry value is the maximum number of concurrent connections to remote X.400 message transfer agents (MTAs). The default value of 6 is sufficient for most organizations. There is a known issue when you use more than 4 EDK Connectors on a server running Exchange Server version 5.5 that requires the value for Concurrent connections to X.400 gateways to be increased to 0x12 (hexadecimal) or 18 (decimal). For more information about this issue, see the Microsoft Knowledge Base article 282115, "If more than 4 Exchange EDK connectors are installed, mail flow stops" (http://go.microsoft.com/fwlink/?linkid=3052&kbid=282115). Unless you are experiencing the issue described in that article you should leave the Concurrent connections to X.400 gateways registry value set at 6.
To correct this, revert to the default configuration
Open a registry editor, such as Regedit.exe or Regedt32.exe.
Navigate to: HKLM\System\CurrentControlSet\Services\MSExchangeMTA\Parameters
In the right pane, locate and double-click the Concurrent connections to X.400 gateways value.
In the Value data field, enter 6, and then click OK.
Close the registry editor and then 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" (http://go.microsoft.com/fwlink/?linkid=3052&kbid=256986).