Someone on the postgrey list (Matthew, who apparently likes drinking coffee, as that is part of his email address) sent a script that he uses to report on his mail/spam. 

I modified it to work on my systems (and included it below), and here is the output for the last five days:

Rejected by RBL: 21147
Rejected by greylisting: 9917
Rejected by bad sender/receiver information: 959
Tagged as spam: 1457
Real email: 6278

So, ~4000 (50%) are rejected every day simply by being on a known blacklist, ~2000 (25%) are slowed down by greylisting (maybe are retried, maybe aren't), ~200 (2%) due to the spammers faking from or to addresses (or real people mistyping addresses), ~300 (4%) ending up in spam folders, and ~1200 (16%) actually ending up in inboxes.

Taking the inverse of the inbox mail, that means that 84% of email coming into my server is being thrown away one way or another.  I'm glad I have lots of filters to block almost all of it.#!/bin/sh

LOGS=/var/log/mail.log.*.gz

echo -n "Rejected by RBL: "
zcat $LOGS | zgrep -c ' 554 5.'

echo -n "Rejected by greylisting: "
zcat $LOGS | grep -c ' 450 4.2'

echo -n "Rejected by bad sender/receiver information: "
zcat $LOGS | grep -c ' 450 4.1'

echo -n "Tagged as spam: "
zcat $LOGS | grep -c 'result: Y'

echo -n "Real email: "
zcat $LOGS | grep -c 'result: .'

Posted by Jon Daley on December 26, 2007, 3:11 pm | Read 2789 times
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Comments

Well I'm beginning to find that mail servers not from big companies get blacklisted for no good reason. So be carefull with that.

Posted by Mike on January 2, 2008, 4:07 pm

What blacklist? I only use the list from spamhaus - and they are quite conservative. spamcop is useful for tagging mail, but not for blocking - and they say that in their instructions. It seems the other blacklists are similar - they aren't good enough for straight blacklisting, but only tagging.

Posted by jondaley on January 6, 2008, 5:20 pm
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