I spent (or was it wasted?) some time the other day reading the comments to the Another Millionaire Spammer Story posted on Friday. I don't think I get too much more spam than anybody else, and I get considerably less than other people, but something about the behavior of these sort of people just drives me nuts.
I think people like Ralsky are an unfortunate side effect of capitalism. They take advantage of a system designed for the benefit of everyone (email) for their own personal gain. It's a classic tragedy of the commons situation. Even those of us who don't buy what he's peddling pay in terms of lost time, bandwidth and other resources in our efforts to ignore them.
I think there has to be some way to eliminate this problem that doesn't simply relegate spam to the background where it still clogs the networks. That was part of why I posted this thought experiment in the comments. I was motivated also by a posting I read a few months ago from Paul Prescod demonstrating the structure for a RESTful email system. I even downloaded and read the SMTP rfc in an attempt to discover the "flaws" that allow spammers to inundate us with impunity. I don't really know enough about the TCP/IP architecture but I think the problem stems from the inability of a receiving server to positively verify the sending server's location. Indeed, SMTP allows a sending server to not identify itself at all. I think that if we could guarantee a valid return path for every sent message, spammers would be unable to exist for very long.
Here's one suggestion though. I don't think I'm the first person to come up with it either. Turn off all vestiges of html mail in your mailer. Something like 99.99% of all my spam email comes in the form of html. Spammers use html for all kinds of nasty tricks like web bugs and unexpanded entities that aren't caught by filters. In addition, something considerably south of 1% of my non-spam email need be html. If fact, I can't think of a legitimate reason anyone should need to send me an html formatted email message. The major mail client programs all seem to have html mail turned on by default. I can't figure out how to turn it off in my Outlook Express client. Why do the mailer programmers do this? Please at least make plain text the default setting.