XCON: 2026 and 3016 Warnings During Periods of High Server Use

During periods of high server use, the following error messages may be logged in the application event log:
Mail flow is not affected by these messages.

This problem can occur when the system attendant writes to the message tracking log (located in the Tracking.log folder under Exchsrvr). When the message transfer agent (MTA), Internet Mail Service, or other service sends these messages to the system attendant, the system attendant holds the messages in a buffer and only writes to the log if a number of messages that is specified in the registry (the LogFlushFreq registry value) is reached. The system attendant spends less time waiting for disk input/output to finish if you increase this buffer, which reduces or eliminates the 2026 and 3016 event IDs.

The default value of the LogFlushFreq registry value is 0x10 hexadecimal (16 decimal).

To resolve this problem, increase this buffer by changing the LogFlushFreq registry value:

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 LogFlushFreq value under the following key in the registry:
   HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\MsExchangeSA\Parameters
3. On the Edit menu, click DWORD, type 100, and then click OK.
4. Quit Registry Editor.

Stop and restart all of the Exchange Server services so that this change takes effect.