As per Microsoft: "This is by design. Network problems may be preventing messages from being delivered or the message transfer agent (MTA) service may have stopped". See MSEX2KDB for additional information about this event.
Build a great reporting interface using Splunk, one of the leaders in the Security Information and Event Management (SIEM) field, linking the collected Windows events to www.eventid.net.
Obtain enhanced visibility into Cisco ASA firewall logs using the free Firegen for Cisco ASA Splunk App. Take advantage of dashboards built to optimize the threat analysis process.