We have an End of Life Version of Symantec Mail Security for Microsoft Exchange (5.0) installed but it is no longer working. It is currently unlicensed and definitions are very out of date. However, the company is also subscribed to Trend Micro Hosted Email Security and Cisco Content Security within ASA firewall - mail is filtered by both before arriving at the internal Exchange database. The Exchange 2003 server , running on Microsoft Windows 2003 Server Standard, has OS protection through Symantec Corporate Edition 10.1. With the Trend and Cisco CSC filtering enabled and updated, is there a need for an additional AV/SPAM layer for the Exchange Store?