Re: [cobalt-users] Raq550: Need Spam Filter advice

["Dom Scott" <dom@xxxxxxxxxxxxxxx>]

----- Original Message ----- 
From: "John D. Gorena" <Support@xxxxxxxxxxxxxxxxxxx>
To: "Cobalt-Users List" <cobalt-users@xxxxxxxxxxxxxxx>
Sent: Wednesday, August 06, 2003 3:51 PM
Subject: [cobalt-users] Raq550: Need Spam Filter advice


[snip] Many of these spam messages come
> from many different IPs and I have manually blocked hundreds.  They do
> seem to link to the same few websites.

I wouldn't permenantly block IP addresses if I were you, as firstly an IP
address is not permenant, so someone else might take over that IP and have
all their mail rejected from your mail server.  Also if the owner of that
server stops the breach then they have no way of getting off that list
again.  A more sensible option is to use DNS blacklists like SpamCop which
are based on domain names and are constantly updated.  This means that they
don't stay on the list unnecessarily, and because lots of people contribute
to them, they tend to be fairly up to date.

> It is these emails that I want
> to deny so that they get the messages back.

The easiest way of doing this is to set up a DNSbl for sendmail to check
mail against (have a search through the archives, this was covered fairly
recently), but it's not 100% effective and it only goes on the domain name
sending the email.

> Any programs that will allow me to do this?

However, there is a very cool piece of spam filtering software called
SpamAssassin.  It does all of the stuff you want and then some.
www.spamassassin.org should tell you more.  You can combine it with procmail
(already installed on your RaQ) to either move spam to wherever you want,
delete it and probably bounce it too, although that might take some extra
work.

Parker Morse has done a fantastic HOWTO at
http://bluebird.sinauer.com/~morse/cobalt/procmail.html on how to install a
separate version of Perl and SpamAssassin.

Hope this helps :)

Dom