After you install Endpoint Protection 12.1 or later, a Mail Security or Scan Engine product on the same computer no longer receives new virus definitions.
In previous versions of Symantec Endpoint Protection, the virus definitions were shared between the virus protection client and other Symantec products that used virus definitions. In Symantec Endpoint Protection 12.1 and later, this is no longer true. Other Symantec products that use virus definitions must be configured to update separately from Endpoint Protection.
For instructions on how to configure your Symantec product with Symantec Endpoint Protection 12.1 and later, read the document appropriate to your product: