XCON: Exchange Server MTA Blocked by Very Large Message

• Microsoft Exchange Server versions 4.0 and 5.0

SYMPTOMS

Microsoft Exchange Server may stop delivering messages; no error messages appear. The message transfer agent (MTA) cannot be stopped by using the Control Panel. When you look at the MTA CPU time in Performance Monitor, it is constantly at 90 percent or more. After several hours, the MTA comes back to normal operation. This is caused by a very large message that corresponds with a large DAT file in the Exchsrvr\Mtadata directory.

CAUSE

The MTA is very busy while performing content conversion code when dealing with very large text message body-parts. The issue does not occur when processing messages with large attachments.

STATUS

Microsoft has confirmed this to be a problem in Microsoft Exchange Server, version 4.0 and 5.0.

A supported fix is now available, but has not been fully regression tested and should be applied only to systems experiencing this specific problem. Unless you are severely impacted by this specific problem, Microsoft recommends that you wait for the next Service Pack that contains this fix. Contact Microsoft Technical Support for more information.