VIPRE Email Security's Attachment Filter can be configured to ignore internal messages:
  1. Open VIPRE Email Security's Console
  2. Go to: Polcies and Recipients > Attachment Filter > Default Attachment Filtering Policy > Rules (Tab)
  3. Select "Add" (For a specific type of file, click Smart rule then select it from the list)
  4. Make sure Allow is selected and Uncheck Scan inside allowed archives
  5. Under "Message Path" select Inbound Internal and Outbound Internal
  6. Click OK to create the rule.
Once this rule is in place, all internal messages (or messages with the specified attachment type) will be excluded from the Attachment Filter.