Graham's article</a> describes this idea much more
thoroughly than I can here. Basically though, I would
be interested in an option that lets bogofilter
retrieve URLs in mail either: always, when unsure of
status, or never. If the URL is retrieved, tokens
found on that site would also be processed by
bogofilter to determine spam status. Links found on
that site would be followed and processed to n levels
of recursion, where n is also user-specified.
As mentioned in Paul's article, presuming enough people
adopt this strategy, a nice side effect of it would be
that spammers' websites would get slammed with traffic
every time spam was sent out.