Most of the problems that cause the MTA to fail to start are related to the contents of a message. If the MTA will not start, try stopping the information store prior to starting the MTA. If the MTA then starts, start the information store and monitor the server. Always check the Event Viewer to get additional information. If there is a problem with one of the files in the MTA database, an entry will be made in the application event log. It may be necessary to remove a file from the database if it is causing problems.
If the MTA does not communicate with MTAs on other servers, wait at least 10 minutes. The MTA is designed to reset the association and retry the connection after 10 minutes. Stopping and starting an adjacent MTA may cause the process to "wake up" and recognize that the restarted server is available.
If the MTA service starts but messages remain in the work queue, use Performance Monitor or the Microsoft Exchange Server Administrator program to determine the destination. This will provide the information needed to continue the troubleshooting process.