Eric writes: > For example, Hotmail and AOL exchange mail directly > already, and they could use SMTPng for these exchanges > and immediately start to take advantage of the available > features, regardless of what they use to talk to the rest > of the world. True ... but unless they are already sending a lot of spam to each other today, what would this accomplish? > My guess is that the 80/20 rule probably applies to email, > in that 80% of the messages are probably routed through 20% > of the mail servers, and getting a sizable portion of that > 20% would likely be enough to capture most of the messaging > network. I agree, but I also suspect that most of the world's spam is routed outside that 20% of mail servers, so I'm not sure what this would accomplish. > My feeling is that the whole effort would be much more > likely to succeed if it were a from-scratch design. Like PNG, IMAP, JPEG2000, and so on ... all of which are taking the Internet by storm, as we all know. The more discussion I see of technical solutions to spam here, the more I tend to believe that no technical solution will work. Participants in this discussion, for the most part, clearly do not have a handle on the fundamental problem of spam, and incorrectly believe that some magic, machine-verifiable characteristic of a message will allow it to be identified as spam rather than legitimate e-mail. But the only difference between spam is in the interpretation made of it by its human recipient, and that cannot be encoded in any machine language. Every technical solution mentioned thus far will allow spam to continue, and will also cause the loss of legitimate e-mail.