Re: An Anti-Spam Heuristic

>You might want to look at hashcash. http://en.wikipedia.org/wiki/Hashcash
>
>Brief summary of the conclusion: cannot work, as spammers have much easier
>access to free CPU cycles than do legitimate senders of mail.

I wrote a white paper about e-postage eight years ago, which has stood
up pretty well.  There are other fatal issues, related to the need to
whitelist mail from people whose mail you want to get.

http://www.taugh.com/epostage.pdf