April 20th: We have completed another significant update to the
that we use. This update adds Challenge/Response, domain-wide
spamassassin settings, and the capability to make advanced
spamassassin configuratiion changes.
In brief, the challenge/response system
causes the mail system to queue messages from unknown senders,
and to send back a message (a challenge) to them. The message
asks them to respond (the response, see where
the "challenge/response" name comes from?) to the challenge. When
they do, they are marked as valid senders, their queued messages
are forwarded, and any future messages they send are passed
The domain-wide SpamAssassin settings allow the administrator
to configure the default SpamAssassin thresholds, the default black
and white lists, as well as tweak the advanced settings for the whole
domain (see next paragraph).
The advanced SpamAssassin settings allow users to re-configure
SpamAssassin. This includes change scores for the various rules,
possibly adding new rules, etc. This isn't to be done casually.
Please read the documentation at