The other question I have about Yahoo is why it has refused to implement SPF. Sender Policy Framework is the uncontroversial part of Sender ID, the part that checks the message envelope. Many people still argue that SPF is all we really need. But no serious people believe this, least of all SPFs author Meng Weng Wong, who is a principal author and sponsor of the Sender ID spec and also a fan of DomainKeys. All SPF really stops is bounce messages, also known as "Joe Jobs." Its an important part of the solution, but its far from an adequate one.The Yahoo announcement focuses on phishing, probably because its topical. Spam has become a major annoyance, but phishing is scary. And SPF does nothing to address phishing. This is why Microsoft developed Caller ID, the header portion of Sender ID. I should also take a moment to wag my finger at those who continue to express concern at how spammers are adopting SPF and other authentication standards in order to get around them. I dont know if theyre walking into a trap or if theyre just experimenting, but it wont do them any good. The more spammers authenticate, the easier they will make themselves to block. For insights on security coverage around the Web, check out eWEEK.com Security Center Editor Larry Seltzers Weblog. Remember, authentication systems are not complete anti-spam systems. They just identify who is sending the mail, not why they are sending it. This whole approach requires the coordinated use of reputation systems that will use the authenticated address to tell you whether a sender is trustworthy. In such a scenario, an authenticated spammer becomes easy to block. The collapse of MARID brought forth a call for experimentation with the various proposals in the hope that the experience would inform the standards process and help to produce a consensus. Were lucky. The experimentation so far has formed along the lines one would expect, meaning the proposals backed by the major players. The advancement of DomainKeys puts in an approach that the open-source community wont object to and that is forward-looking. It doesnt have to be the only success in this area, but its good that we have it. Security Center Editor Larry Seltzer has worked in and written about the computer industry since 1983. Check out eWEEK.coms for the latest security news, reviews and analysis.
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But it is an easy one, and theres no good technical reason why Yahoo should resist it. All the other major mail providers, to my knowledge, are implementing SPF as part of their experimentation. The answer for Yahoo is probably something as stupid as not wanting people to get the misimpression that they are hedging on DomainKeys. I asked the company about this several weeks ago, and it weaseled out of a direct answer. Most dissatisfying.