is it possible to whitelist specific senders for banned
files only?

I"ve added some senders to the conf file like this:
map { $whitelist_sender{lc($_)}=1 ) (qw(
     list of senders
I presume this is all I have to do, what I find is that mails sent from
the whitelisted senders get blocked when they include a banned file.

Any help would be greatly appreciated,