http://www.antipope.org/charlie/blog-static/2011/10/pink-stuff-patrol.html

spam control

TRX
October 16, 2011
98:
Charlie mentioned:
>word salad spams

Years ago I looked at valid incoming email versus spam and realized that a simple grammar checker could catch the majority of it. At the time I didn't find anything, but DOS grammar checkers were available in the 1980s, so I expected some type of filter would be available to filter between the MTA and MUA.

Hmm, a quick web search shows a couple of possible candidates now. I might check them out if I get the urge to join some mailing lists again. I don't know if it's a practical method for filtering on a blog, but given the literacy level of the people who post here I would expect it would be very effective.