We have a CSC-SSM module with the plus license installed. It's installed and configured to work in a Cisco 5510 router.
It does filtering but from a functionality perspective - it seems as though it does not actually send and or receiving anything on it's own - rather than just pass through traffice through the module and assigned rules. We have a cisco spam and virus blocker, that acts the same way, however it functions basically as in internal to external, and external to internal hub transport server for SMTP traffic.
Does the CSC-SSM module have the same functionality - it seems not.