It's not clear to me what the target audience of this article is. It seems to assume everyone knows what greylisting and greytrapping are; but surely the peopl

It's not clear to me what the target audience of this article is. It seems to assume everyone knows what greylisting and greytrapping are; but surely the people who know what those terms mean without explanation are already convinced? I picked up from context the general idea behind "greylisting", although I'm sure there's a lot of details that aren't covered. (How do you chose what domain gets greylisted? How often, how long?). But what "greytrapping" is, I can't guess, even after reading the entirety of two of his articles.