I've got a question that probably sounds naive, but, what on earth is the purpose of spam? And who the fuck produces this shit? It has to have some commercial connection because the quantity is simply too vast for a few thousand jerks. The industrial volume implies it is indeed an industry. It has to be paid for to be produced in this volume and ubiquity. So what is the industry like? Who runs it and what for? And another thing. About 99% of it is html and looks like it came from M$uck servers running Exchange. That also implies a cheezy commercial base.
I have to go to my spam filter file on a shell account and delete the file at least twice a week. It is usually in the 10-15Mg range. That's a tremendous amount of garbage. If I let it go for a week it starts to get large enough to threaten an isp bot notification of nearing the account disk space limit.
The volume seemed to take a much steeper increase about two or three years ago---about the same time there was finally some news talk about legal restrictions. Recently, it has taken a new leap forward into the astronomical
Also it seems to have changed topics over the years. I remember the good old days when it was just stupid porn ads. After that it went through financial phase with loan-con-jobs and investment schemes. Now days it seems cheap drugs from Canada or Mexico are the favored themes.
CG