Yes, but better still, join up at http://www.trustic.comI just signed up with Trustic last week and your idea of sending doublebounces to Trustic automatically is brilliant!
You can then forward those double bounces as attachments to the address they give you and volia, you add to the anti-spam listing.
Also, set your qmail-smtp run file like this :-
exec /usr/local/bin/tcpserver 0 smtp rblsmtpd \ -b -c -r sbl.spamhaus.org \ -b -c -r relays.ordb.org \ -b -c -r QUERYADDRESS \ qmail-smtpd 2>&1
Replace QUERYADDRESS with your trustic assigned one.
-- Aj. Systems Administrator / Developer