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


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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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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