In theory, it's a great concept: put the burden of costs on senders, and you immediately wipe out the profits of spammers. And if you make the cost per email a fraction of a cent, it is simultaneously high enough to eliminate spam while low enough not to interfere with the permission e-mail marketing efforts of responsible e-mail marketing professionals.
The difficulty with the theory is its application, of course: who will manage the micro payments? Where does the money go? And who sets the rates? That's why I believe a better solution involves making email senders pay in terms of time, not money, to send e-mails. This can be accomplished by requiring mail servers to perform time intensive calculations when sending each e-mail. Every outbound e-mail is stamped with the result of the calculation, and receiving e-mail servers can verify that the email in question has been sent by a complying server.
This solution, which is called the "Penny Black" solution, has been under development at Microsoft for quite some time. If this became reality, it would require updates to every mail server on the Internet, but it would also be a near magic bullet solution to the spam problem. If large ISPs like AOL, Yahoo, and MSN stopped accepting e-mail that wasn't Penny Black compliant, every IT administrator in the world would update their mail servers virtually overnight. The result? A spam free world, or at least as close as we'll ever get.
This solution would make spamming prohibitively expensive. Spammers would have to buy hundreds of mail servers and run them 24 hours a day in order to produce any sort of email volume whatsoever. And with profit margins for spammers already quite narrow, this solution would eliminate the spam profits altogether. Furthermore, this solution does not require a highly complex payment system which would undoubtedly be a nightmare to create and administer. But it does require a secure algorithm that cannot be hacked or counterfeited by spammers, because if just one person breaks the code and manages to send out Penny Black compliant e-mail without having to spend the associated CPU time normally required, the whole system falls apart, and we are all back to square one.
Yet we now live in the online equivalent of a no-postage world, because
the cost of sending electronic mail is so near to zero that spammers
thrive when only a handful of suckers respond to the millions of
messages they send.
There's an obvious and tempting answer: Create an e-mail postage system
that charges senders a tiny amount, perhaps just one-tenth of a cent a
message.
Internet service providers, or ISPs, could give their customers a
generous number of outgoing messages for free -- say 1,000 a month -- so
most e-mail users might never notice the change.
There's a glimmer of hope, however, as the biggest ISPs begin to
recognize that radical action may be necessary to stop spam at the
source.