The Microsoft CRM Email Router service on Local Computer started and then stopped

The Microsoft CRM Email Router Service will not start every time you start it manually from Services and throws an error message “The Microsoft CRM Email Router service on Local Computer started and then stopped. Some services stop automatically if they have no work to do, for example, the Performance Logs and Alerts service.”

Event log entries say:
Event Type: Error
Event Source: MSCRMEmail
Event Category: None
Event ID: 0
Date:
Time:
User:
Computer:
Description:
#16192 – The E-mail Router service could not run the service main background thread. The E-mail Router service cannot continue and will now shut down. System.Configuration.ConfigurationErrorsException: The E-mail router service cannot access system state file Microsoft.Crm.Tools.EmailAgent.SystemState.xml. The file may be missing or may not be accessible. The E-mail Router service cannot continue and will now shut down. —> System.Xml.XmlException: Root element is missing.

This means your Email Router configuration file is corrupted.

You need to go to C:\Program Files\Microsoft CRM Email\Service and delete the Microsoft.Crm.Tools.EmailAgent.SystemState.xml file. Try to re/start the Email Router Service. This should resolve your problem.