This Knowledgebase article provides an overview of the Neverfail Application Module eXtension (AMX) for Symantec Mail Security for Exchange identifying the features and benefits of this product. Additional detailed information is contained in Knowledgebase article #670 - 'Symantec Mail Security for Exchange – Application Module eXtension – Feature List'.
There is a sister article ( Knowledgebase article #563 - 'Symantec Mail Security for Exchange – Application Module eXtension – Versions') that lists all of the current and supported versions of the AMX and the versions of related supported software.
Symantec Information Foundation Mail Security for Microsoft Exchange (formally Symantec Mail Security for Microsoft Exchange) provides anti-virus and anti-spam mail scanning for Microsoft Exchange 2003 and Microsoft Exchange Server 2007 and works on 32-bit and 64-bit platforms. The AM(X) protects the Symantec Mail Security services and server configuration running on the File Level anti-virus product from this vendor.