qmail filter

[kentborg at borg.org (Kent Borg)]

On Thu, Feb 07, 2002 at 09:56:54PM -0500, Anand A Rao wrote:
>    can any one help me with a good spam filter script (if u are using one).
> I need to filter those irritatimg spams , and keep my mail box clean. I am
> hooked to pair.com , which runs qmail.

There is no such thing.  But something that might come close for many
circumstances is Active Spam Killer <http://www.paganini.net/ask>.  It
(and I think some other similar packages) only lets e-mail through
from a "whitelist" of known non-spammers.  It will barf on any
messages from anyone on the "blacklist".  And the really cool part is
that if it gets e-mail from someone unknown, it will send back a
message asking for a confirmation before letting the first e-mail
through.  As much spam is unreturnable, the confirmation will never
reach anyone and neither will the original message.  And even the spam
that does have a working return address there isn't a real person on
the other end to read the instructions for how to get through to you.

I haven't tried it, however, because I know it will cause me troubles.

First, I host my own domain and feel obligated to actually look at my
postmaster e-mail.  Because postmaster is where one would report
technical problems, I don't think it is wise to put a potential
technical problem on that address.  Much of my spam is double bounces
that or e-mail originally addresses to bogus users, and postmaster
gets those.

Second, and this could apply to anyone, I get some legit e-mail that
isn't sent by a person and so would likely never get the human
handshake needed to get through.  Obvious examples would be when I
order something from Amazon or Travelocity or whatever, I get a
confirmation e-mail.  Or I later get an e-mail telling me of an
itinerary change.  I doubt I would ever get them with ASK as there is
only a machine on the other end and I don't know the machine's address
to put it on the white list.  Or, I get an e-mail telling me I need to
renew my domain name.  I want to get that e-mail, I don't know what
address it will come from from year to year, and I sometimes get spam
from my registrar (I keep telling them "no", they keep saying "ok"),
and that all seems a big mess.


-kb, the Kent who, because he hosts his own domain, currently is
putting spammer's IP addresses in his xinetd no_access list to prevent
further spam, and sending complaints to the provider of those IP
addresses.