[CentOS] postfix and spam, I am impressed

Tue Mar 13 18:05:22 UTC 2012
Les Mikesell <lesmikesell at gmail.com>

On Tue, Mar 13, 2012 at 12:00 PM, Nataraj <incoming-centos at rjl.com> wrote:
> Ok, so it wouldn't work to just use the oldest received, but a smarter
> inspection could check to see weather it actually passed through a
> server owned by the claimed domain.  The reality is that what is need is
> to input this into a scoring system weighted with other spam evaluation
> mechanisms, something like spamassassin.  The downside of spamassasin is
> that it is costly to run and must be run after the message is accepted
> by the smtp server.

MimeDefang runs it as part of its own milter process so you don't
start a new perl for each message  (and multiplexed so there is not
necessarily an instance for every mailer process), and at a point
where you can do an smtp reject based on the content.

> There already exist so many different spam control methods, many of them
> can run at the smtp level and reject mail prior to accepting.  I get
> pretty decent rejection from greylisting.

MimeDefang doesn't do greylisting although the hooks are there if you
wanted to do it yourself.  But, you can run multiple milters and
milter-greylist works OK.

> I would look at the milter that Les mentioned.  I haven't had a a chance
> yet.

I set up the package from rpmforge a long time ago along with their
clamav.  I see they are both in epel now - not sure what you would
have to do to make them work with postfix, though.  I've seen them
mentioned together on the mimedefang mail list, so someone must be
doing it.

   Les Mikesell
     lesmikesell at gmail.com