Has anyone ever tried hacking qmail-ldap to create an smtpd that can look up recipient addresses on the fly and generate "instant" bounces (kind of like sendmail does)? It would add a bit of overhead for successful deliveries, but on my system it would cut down on 30 or 40 thousand extra spam messages per day from entering the queue for processing.
Since I'm not 100% familiar with all of what qmail does to preserve security, I'm not sure why this feature does not already exist (or perhaps it does, and I'm looking in the wrong place). Has anyone here hacked their qmail to do it, or seen a patch that does? Or even better, is there just some huge security hole that would be opened up by doing it that I have missed? Dave
