>I agree and sympathize (and I am the unofficial NetBSD "spam czar",
>hence this reply), but doing so is not as simple as it may appear.

Indeed.  The only real solution will be some time after laws are passed
to class spam as fraud or theft etc. (of the unwilling recipient's 
resources and budget).

Anyway, until then smtpd from obtuse.com does a very nice job of cutting 
down on SPAN and unauthorized relaying.  I'm the host/post master of a
pretty big net here and we have found smtpd has cut our load by 
more than 10,000 msgs per day.  Of that, the bulk is mail from un-replyable 
addresses (usually spam), about 2000 or so relay attempts (each of which
used to result in 100Mb worth of complaints from all over the net :-)
and about 300+ attempts from the well known spamers.

I've had to fix smtpd a bit to cope with the fact that we are forced
to gateway x.400 mail, but in general I'm very pleased with it.

--sjg