Sendmail: How does one blacklist annoying spammers?

[Alan Cox]

On Mon, 28 Jun 2010 03:38:12 -0700
"jdow" <jdow at earthlink.net> wrote:

> From: "Alan Cox" <alan at lxorguk.ukuu.org.uk>
> Sent: Monday, 2010/June/28 02:05
> 
> 
> > I believe that's what SPF is supposed to solve.  Sites advertise in
> > their DNS records which the "official" outgoing email servers are.
> 
> Spammers advertise SPF records of 'the whole internet' (normally split
> into chunks to confuse checkers) and turning on SPF checking naïvely
> simply helps the spam get through.
> 
> >>jdow
> Actually not, Alan. If you are using SpamAssassin simply set the score
> for passing SPF tests at a very low non-zero number, say 0.001. That

Thats no longer naïvely using. If you just install it out of the box you
boost spam which is a bit unfortunate. If anything it seems to work best
to score SPF negatively on the grounds that there are two users of SPF -
certain big ISPs and spammers, and neither of them usually have much
interesting to say ;)

Alan