An updated internet-draft is available from the IETF.
Abstract: «A highly spam resistant protocol is shown, which could be implemented for negligible costs. Accepted email’s do the sender not cost money, not accepted ones do. A decentralized server for keeping track of money and information is needed. The protocol, in which encryption naturally appears and can be used transparently aside of the existing mail protocol, allows to freely distribute your emailadress. The protocol avoids the micro payment problem.»
draft-kruithof-spam-reducing-03 (diff)
Ask, and you shall receive. Vernon took my suggestion and added anchors to the Final Ultimate Solution to the Spam Problem list. After a quick reading of the draft, I nominate it for the following 5: e-postage, senior-IETF-member-5, senior-programmer, senior-programmer-3, senior-programmer-4.