With ORBS recent demise and the commercialization of MAPS, I started
looking for other antispam measures. The most promising I've found is
the Distributed Checksum Clearinghouse:
http://www.rhyolite.com/dcc/
If I'm reading it correctly, the code computes a variety of checksums
on portions of messages coming through your MTA, and sends these to a
DCC server which keeps running counts of each reported checksum; spam
sent to a wide audience would increment the same sums so you could
detect it. Clients can query this and decide what to do with any
incoming message. It has whitelists so that large list mail
(e.g. inet-access) would be excluded from spam consideration.
Seems to be built for integration with sendmail. Anyone using it now
with qmail? I haven't found anything useful searching google for "dcc qmail".
