Daley Ponderings

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: .'