I get lots of spam, and the normal techniques get rid of it. I also get lots of DSNs, which are a mail server's way of telling me it accepted my mail but can't deliver it for some reason. DSNs are ok, but suffer from the problem that someone can fake addresses and get the DSNs sent to another address. Spammers, for example.
The procmail people like to claim that if a person if filtering spam with procmail, then he/she has already lost. By this they mean that accepting spam at smtp-time is a bad idea. Most systems filter mail at smtp-time, and reject the spam right then. This way, they never take the mail and never have to send a DSN. A simple bit of reasoning might be: Never accept mail unless:
Qmail users, on the other hand, appear to have a nasty habit of accepting anything then bouncing it back. Thats nice for the warm friendly internet that qmail was written for (joke) but its less good in these days of spammers. So, if you run qmail, or any mail server, reject at smtp time, don't bounce.
The temptation to compose a standard mail saying "I didn't send this mail, stop bouncing like a moron" and binding a key to send it in mutt is great.
posted at: 16:01 | path: /computing | permanent link to this entry