“None of these do me any good with my current setup, but they
all have something in common: they filter the bulk of the email as
early as possible at the receiving server. This should be more
widely available.“I’d like to see an open source project to build a reliable
email pre-filter along the lines of Ronald’s. Ideally, it could
either run on the same box as an existing email server, or on a
separate box, depending on the volume of spam being filtered.
Ideally, it would have Linux, Windows, and Mac versions, and would
be easily monitored, updated and tuned…”