This service is used by the Event Notification Utility (ENU) to send out email/vocie mail based on specific messages logged to the application event log - most sites don't use it so it's disabled by default. It's also had some problems in the past so it'll be retired moving forward. In 4.0(3) a new tool, Error Monitoring Service, will replace it - more functionality, more flexibility, all that good stuff... this will also be downloadable off www.CiscoUnityTools.com for Unity 3.1(1) and later should folks need it.
