Message filter 6.3

Hi,

I am seeking clarification on the difference in skus / types of licensing for the Message filter 6.3.

In the Symantec pricelist I noticed that there is the Antispam sku and a sku for Antivirus.

What I notice is that the the Antivirus sku says "Symc Message filter Antispam AV 6.3"

Can someone please tell me what is difference? is there an additional feature etc.

All documentation online points to general product & doesnt give a the difference between the types.

Thanks in Advance.