Stopping Spam: We can do better

Eweek's article, "Stopping Spam: We Can Do Better," discusses a three pronged spam defense system: "(i) the current approach plus (ii) authentication of e-mail senders and/or (iii) anonymous bonds bundled with e-mails, payable by e-mail senders and redeemable by e-mail recipients—also allows an easier and less risky transition to a better e-mail environment."

A different approach is described in Slashdot's article, " Novel Method for Universal Email Authentication," which describes using SPF to create a database of authenticated machines.