You install Symantec Endpoint Protection clients on an Exchange 2010 server. You need to configure the recommended exclusions.
Symantec Endpoint Protection 11 RU6 MP1 and above adds exclusions automatically for Exchange Server 2010. In releases of SEP prior to SEP 11 RU6 MP1, scan exclusions for Exchange 2010 need to be added manually per Microsoft's recommendations. Please follow the instructions contained in the article "File-Level Antivirus Scanning on Exchange 2010."