Spam Fighting moved from MUA to MTA - success

merlyn on 2003-11-04T15:32:51

I had been handing $random@stonehenge.com by letting postfix deliver to my procmailrc, which fired up a separate Perl invocation to sort and deliver the mail for each incoming. And test for spam.

The problem is the MIRVs. A lot of mail gets addressed to thereto@stonehenge, barney@stonehenge, merlyn@stonehenge, for about 10 addresses. And this type of spam seems to have greatly increased in the past few months. A burst would come in, and for the next two minutes, I was splitting and forking and SpamAssassin-ing, and loadav would hit 3 or so, and my sublease customers were complaining.

So yesterday, I bit the bullet, and learned about Amavisd, a Perl daemon built around Net::Server, that could pull in SpamAssassin and some virus checkers. I carefully read the "README.postfix" file included in the distro, and set up everything.

Wow, what a difference. Now my postfix/amavisd MTA checks for spam once for the MIRVs, without forking, instead of 10 times with a lot of forking going on. My loadav has never exceeded 0.9! Hooray. Success.

I'm getting about 1 MIRV a minute. Ouch.

My only concern is that the amavisd is started and stopped outside the normal postfix engine, so I'm concerned about what happens when it goes down. (Postfix will just stop, but I won't be around to notice.) I'm thinking of a cronjob entry to just keep restarting it every half hour or so, just in case it fries.


Qpsmtpd

Matts on 2003-11-04T23:16:41

Just do your entire smtpd in perl.

There's two pieces left to the qpsmtpd puzzle - firstly to have a pure perl server (which I've just checked into CVS, but it's a little premature yet - help would be most welcome since this is an area you have lots of experience in), and secondly to have a pure perl delivery system (perhaps delivering to procmail, but also needs to support onward relaying).

Sorry, I hate it when people like me suggest a completely different solution to the one you just found that works perfectly well :-) I'll shut up now.

Re:Qpsmtpd

merlyn on 2003-11-05T02:14:00

There are times when I want a stick shift, and times when I want an automatic.

For email delivered to $FOO@stonehenge.com, I want an automatic. If it was just my own mail, I'd be happy to play with new tools, and take the risks (and rewards of such).

I think you can both relate, and agree.

Spam Fighting moved from MUA to MTA

dominix on 2003-11-30T07:46:23

have you tried MailScanner (yet another Perl-wrapper for SpamAssassin) I enjoy it very much and it has auto-recycling and multiple instance and multiple possible MTA.

-- dominix