XCON: Exchange Server Message Transfer Agent in Large Site May Run Out of Entity Control Blocks

WORKAROUND

To work around this issue, run Performance Optimizer and change the Number of users setting to the number of users that the connector services, rather than the number of users on the local server. Also set the server to be a Multiserver and Connector server.

If this issue still occurs after you run Performance Optimizer, make the following registry changes:

WARNING: If you use Registry Editor incorrectly, you may cause serious problems that may require you to reinstall your operating system. Microsoft cannot guarantee that you can solve problems that result from using Registry Editor incorrectly. Use Registry Editor at your own risk.

1. Start Registry Editor (Regedt32.exe).
2. Locate the Concurrent connections to LAN-MTAs value under the following key in the registry:

   HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\MSExchangeMTA\Parameters

3. The default value is 40 in decimal format; change the value to 80. On the Edit menu, click DWORD, type 80, and then click OK.
4. Locate the LAN-MTAs value under the same key in the registry.
5. The default value is 20 in decimal format; change the value to 40. On the Edit menu, click DWORD, type 40, and then click OK.
6. Locate the Number of Remote Sites Connected over LAN value under the same key in the registry.
7. The default value is 25 in decimal format; change the value to 50. On the Edit menu, click DWORD, type 50, and then click OK.
8. Locate the X.400 gateways value under the same key in the registry.
9. The default value is 20 in decimal format; change the value to 40. On the Edit menu, click DWORD, type 40, and then click OK.
10. Quit Registry Editor, and then restart the MTA.