I've noticed spam which has a section of "extracted" text after the spam content. It seems to me that by taking things line by line, you'll reach a point at which the spam index peaks, and then trails off after. This is a pattern which would remain even if the "overall" spam index is low.
Does the current spam assassin implement such an approach ? Or is the algorithm sufficiently subtle to null out these attempts ? Thanks, -- The issue is not whether we _can_ reduce everything to selfish motives, but whether we _should_. - Paraphrased from Peter Singer John August.