I guess this has been discussed a time or two already, but, as of yet, I haven't found anyone that has found a real solution. We need the ability to have around 1000 domains per physical server, while allowing each domain to maintain their own sender blacklist (using the sender's email address, not IP address).
While I realize that this can be done with smtpd_recipient_restriction, but, on hosts with lots of domains, you end up with a lot of open files (e.g. http://tech.groups.yahoo.com/group/postfix-users/message/241874 ). So... my thought is that a policy server is the answer. However, I can't seem to find a policy server that supports sender blacklisting which is written in C (I'm concerned that anything else wouldn't be fast enough). I'm ready to concede that the solution I'm looking for does not exist, but I just thought I'd check... just in case something new has come on the scene (either with Postfix or with policy servers) since the last time this was discussed. Thanks, Curtis
