Message tracking helps resolve help desk calls by giving a detailed view of message flow. For example, if a message was not delivered as expected, you can determine if it was found to contain a virus or placed in a spam quarantine - or if it is located somewhere else in the mail stream. Reference: https://www.cisco.com/c/en/us/td/docs/security/esa/esa12-0/user_guide /b_ESA_Admin_Guide_12_0/b_ESA_Admin_Guide_12_0_chapter_011110.html