Remove "X-Mail-Scanner: Not scanned" ?

[Richard Curtis]

Hi again.
  Is it possible to configure mailscanner so that if (via a rule set) it
doesnt scan an email for virus's, it doesnt add the above header.
I am noticing that on emails not scanned, the headers:
X-Mail-Scanner-Information: Please contact the ISP for more information
X-Mail-Scanner: Not scanned: please contact your Internet E-Mail Service
Provider for details
X-Mail-Scanner-SpamCheck:

are all added... it would be nice if it simply didnt modify the headers in
any way if scanning is disabled for a given domain etc.

Richard