As per Microsoft: "This issue may occur if a firewall blocks the binary large object (BLOB) data following the Microsoft Exchange Server XEXCH50 command". See ME818222 for a workaround.
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.