possible useful feature

[thebet at tin.it]

Hi.
Just thinking about a particular scenario. Imagine a ISP of course 
with roaming users and implementing DNSBL with mailscanner.
And this 
ISP usedrac for pop before smtp support.
But....sometimes these roaming 
users are listed on some DNSBL (when some user1 at domain writes to 
user2 at domain fo example).
Not good. So ISP have to create whitelist 
based on source mail address. Not a great solution.
Would be nice to 
avoid dnsbl checks if source IP are listed on drac db.
milter-greylist 
too is implementing this function in their develop release.
Comments?