> Been there, tried that. I've had mx2.freebsd.org soft 4xx blocked for 1 > day at a time for over a week. Besides the increased number of connections > to my server, using a 4xx error makes almost no difference. As soon as > the penalty box expires, the queued ham and spam pour in and mx2 gets > tossed back into the penalty box. For most messages, a 4xx error ends up > being the same as 5xx error except with a delay.
I don't know if I'm typical, but I would personally be very hesitant to reject or even defer a server such as mx2.freebsd.org, which is known to send legitimate mail, even if I know that it is going to try to send some spam as well (assuming of course that it is not intentionally originating the spam or infected with a trojan/botnet, at which point it could no longer be called a legitimate server). I would be more inclined to use the 'penalty box' to filter out illegitimate servers, and rely on content filtering to do as much as can be done about spam on legitimate mailing lists, etc. A server operated or controlled by spammers or botnets is not going to retry messages indefinitely like this, so it should be much more susceptible to a 'penalty box' regardless of whether you reject or defer. -Jared
