MTA in an Uncontrollable State; MTA Service Can't Be Stopped

It is possible that the message transfer agent (MTA) may enter an uncontrollable state. In some instances, it cannot be stopped with the interface in the Control Panel, Services tool. This may be caused by a corrupted message entering the MTA database for processing or by a corruption within the MTA database itself. Another possible cause is an excessively large message entering the server from the Internet. Messages are not processed by the MTA while it is in this state, and they queue up in their respective queues.

While the MTA is in this uncontrollable state and cannot be stopped through normal procedures, the Exchange Server Administrator program itself may not be accessible. In fact, when you try to access the Administrator program, you may see a Busy icon. Furthermore, if you try to stop the System Attendant service, it may also be in an uncontrollable state.

To resolve this issue:

1. Try to stop the MTA through the Control Panel, Services tool. Give it enough time (five minutes at least) to make sure the service has actually stopped responding. If it does not stop gracefully, proceed with the next step.
2. Use the Windows NT Task Manager, and on the Processes tab, find the EMSMTA process. Try to end the process by clicking the End Process button at the bottom right corner. Make sure you are logged on using the Exchange Site service account while performing this step.
3. Note the process ID for the EMSMTA process from the Processes tab in the PID column. Use the Kill.exe utility to kill the MTA at this point. The Kill.exe utility can be found on the Windows NT Resource Kit CD. From a command prompt type:
   Kill Process ID found in task manager's PID column
   -or-
   
   
   Kill emsmta
4. After the MTA is stopped or killed, run Mtacheck.exe twice. Mtacheck may find corrupted messages or queues. If it does, run it again until it says "Database clean. No errors detected." For additional information on running Mtacheck, please see the following articles in the Microsoft Knowledge Base:
   148284� XCON: When and How to use the Mtacheck Utility
   149017� XCON: MTACheck Event IDs and Command Line Syntax
   163326� XCON: How and Why to Run Mtacheck
5. Re-start the MTA. The service should start and begin processing mail. Processing the backlog may be slow depending on the size of the queue.

If there are several thousand messages, it may be helpful to run Mtacheck with the /rd switch. This takes some of the processing load from the MTA. The deleted directory replication messages are regenerated by the Directory service.

NOTE: The MTA may not start if there is some higher-level corruption within the MTA database or any other severe problems with the MTA. If this is the case, please contact Microsoft Product Support Services.