In Part 1 I took a “from first principles” look at the spam problem, and concluded that the only way to actually solve the problem was to make people pay to send e-mail.
Now, it’s time to look at what I mean by that—because there are almost as many ways to implement “pay to send” as there are ways to implement filtering.
This is going to be a bit more technical than part 1. I’m going to assume you know basically how SMTP e-mail works. If not, there are tutorials available.