From: Bob H. <hut...@mi...> - 2005-01-29 11:06:09
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On Friday 28 Jan 2005 19:31, Kenneth Andresen wrote: > Hello all, > > I have hosted a free web-based squirrelmail e-mail service for a few > years, without any problems, however got my first incident of a spammer > using my system a few days ago. It turned bad, and I am already in > multiple block lists... > > I want the service back up again, but for that I need to be able to > filter outgoing messages for spam and viruses. I would like the ability > to use procmail for filtering as it makes it easier to add new filter > tests adding rules for spamassassin, clamav, and so on dirrectly in the > procmail script. > > If content is not accepted, procmail can also notify the server admin > with the violating content, freeze the account for review, and even > block the violators ip in case he tries sending again from same ip with > a different account. > > The only thing I need is thus a plugin to intercept the outgoing > messages with procmail. > > How can I make such a plugin? Or maybe you have recommendations for how > I may accomplish this easier? You need to do this at the SMTP level for your MTA, tarpitting is a technique that springs to mind, pop-before-smtp would make life awkward for spammers too. Some firewalls can rate-limit on a per port basis, so if someone sends more than say 50 mails concurrently it slows right down, putting x seconds between each mail. Customers running home-based mailing lists will have to use mailinglist software on the server, eg mailman, majordomo, ezmlm. That way puts you in control. HTH -- ----------------- Bob Hutchinson Midwales dot com ----------------- |