spam removal

[Paul A. Hoadley]

On Mon, Feb 16, 2004 at 04:44:25AM -0500, matthew wrote:

> > I recommend bogofilter for per-user filtering.  Spamassassin is
> > also highly recommended for site use.  I tend to dislike DNS-based
> > filtering because it has a high rate of false positives, and it
> > causes your users to lose legitimate mail if it's rejected at the
> > mail server.
> 
> As far as I understand it, one does "not lose email" using dns-based
> blacklists.

Sure you can.  If Alice wants to legitimately contact Bob from a
blacklisted IP (whether the blacklisting is actually Alice's fault, or
she's just fallen under an excessively large blanket), and Bob is
running DNS-based filtering, Bob's MTA blocks Alice based on her IP.
Bob loses legitimate mail.  Admittedly you provided a counterexample,
but it is not always so easy.


-- 
Paul.

mailto:paulh at logicsquad.net
mailto:phoadley at maths.adelaide.edu.au