From mboxrd@z Thu Jan  1 00:00:00 1970
From: steve@quintile.net (Steve Simon)
Date: Wed, 20 Sep 2017 23:54:34 +0100
Subject: [TUHS] Who is running their own mail server and what do you run?
In-Reply-To: <8060db09-60d9-8113-ac4e-a7298211baf1@kilonet.net>
Message-ID: <1274eb5fe2051d0052af14155ba75a0a@quintile.net>

My spam filtering is all plan9 based but the ideals are all portable.

Greylisting and delaying a few secs before starting the SMTP
conversation are my most successful filters, After this comes
SPF and using spamhaus to validate the senders IP.

I reject some silly domains like localhost.com and usernames like
user and test.

I also have a list of regexps which match the reverse dns
addresses of adsl blocks which catch many spam bots.

The regexps sound like a lot of work but I have some scripts to
analyse my logs and suggest  patterns, so its just a click or two
I can block somthing like:

	dhcp.[0-9]+.[0-9]+.[0-9]+.[0-9]+.adsl.nasty-isp.net

-Steve