[Spambayes] [spambayes-dev] milter implementation of spambayes

[T. Alexander Popiel]

In message:  <4277.81.11.192.161.1222386422.squirrel at intrepid.warp.be>
             "Amedee Van Gasse" <amedee at amedee.be> writes:
>
>I'm wondering if it is possble to create a milter implementation of
>spambayes.

It's possible, but not particularly useful.  Sure, you could tell a
well-behaved sender that you're rejecting the message, but spammers
are not well-behaved senders.  In typical spammer setups, immediately
after the entire message body has been sent, the sender closes the
connection without waiting for a response.  Spambayes needs the entire
message body for scoring, so by the time a spambayes score is available,
the spammer no longer cares, and has moved on.

At most, you'd be informing well-intentioned senders of false-positives
that their messages were rejected... and they could at that point try
to resend through alternate means.  However, in my experience, the
senders who would benefit from such are the same senders who tend to
resend anyway, when they don't get the expected reply to the message.

Where things like milter really help is when you can reject simply
based on some combination or subset of sender IP, sender's claimed
from address, and recipient address.  If you can form a decision just
based on those three things, then you can reject before the body is
sent (while the spammers are still listening).  In lieu of rejection,
you can also do fun things like tarpitting the connection, giving them
a transient failure (ala greylisting), or similar manipulations.

Unfortunately, I don't know any of the actual mechanics of milter,
so I wouldn't be a good source of implementation cluebats.

- Alex