[mdlug] AntiSpam Tools

[Rich Clark <rrclark@rrclark.net>]

On Wed, 5 Dec 2007, Dave Arbogast wrote:

> Hi Mike, I use Postfix with Spamassassin, but do several things up 
> front. In the main.cf file I block SMTP handshakes from quite a few 
> countries with:
> 
> smtpd_client_restrictions =
>         permit_mynetworks,
>         check_client_access hash:/etc/postfix/access,
>         reject_unknown_client,
>         reject_rbl_client sbl-xbl.spamhaus.org,
>         reject_rbl_client zen.spamhaus.org,
>         reject_rbl_client ae.countries.nerd.dk,
>         reject_rbl_client am.countries.nerd.dk,
>         reject_rbl_client ar.countries.nerd.dk,
>         reject_rbl_client ao.countries.nerd.dk,
>         reject_rbl_client ad.countries.nerd.dk,
> and many more for countries I do not have friends / clients in. Of 
> course the biggest offenders were CN, HK, KR, IT, JP, MX, and some 
> former USSR countries. Notice the unknown client and spamhaus blocking. 
> The good thing about this is there is little processing on my end as the 
> message is never accepted. I also have some header restrictions for a 
> few specific offenders and former addresses I had hosted - this too 
> prevents processing at my end. I have some class B and C networks listed 
> in the access list to block when they are problematic senders who pay 
> enough money that their US ISP will not block them.
> 
> My domain has been out there since 1996, so there are many blasts to it 
> hourly. I have the same email address now for about 6 or 7 years at my 
> domain and now only get about 0 - 2 spams per day with these measures.

Grin... sounds like my own setup and results. Highly recommended. Get 
FuzzyOCR and RulesDuJour plugins for spamassassin and add to the fun.