Hi Reuven, Also check my own modification of check_delivery which uses vpopmail/mysql to check for the existance of users in real-time instead of you having to maintain a list of bad users manually (which is a pain in the *ss). I had the same problem you mentioned, only with a slightly larger setup (about 300 domains), so maintaining a list was out of the question.
Take a look at this overview: http://qpsmtpd.nsa.co.il And also here: http://gw.nsa.co.il/qpsmtpd/ (in this last one, look for check_delivery, and its scripts: dot-qmail-exists.pl and vpopmail_user_check.pl). The original check_delivery did not respect catch-all and aliases, I had to fix that as well. Aric
