In the fullness of time, the universe itself will die of heat. So what?
How come this makes me want to raise the issue of our immortal souls?
spammers have souls?
So for example saying this or that filter appears to have repelled 1M spam msgs per day doesn't really prove much unless one can say with some (preferably mathematical) confidence that it's actually reduced spam not just caused it to flow around the filter.
Put another way it'd be nice to know that a technical approach was statistically superior to just shutting off SMTP for an hour per day which would also block some amount of spam. Look! Not one single piece of spam from 1AM-2AM (while we had our machinery all turned off.)
i measure success by the fraction: rejected_spam / total_spam thus if i can reject 6000/10000 that may not seem better than rejecting 1000/4000 since i ended up dealing with 4000 received spams rather than 3000, but it actually does mean that my situation got better _compared_to_having_done_nothing_. (those are weekly figures for my own personal server; hotmail sees the same numbers in less than one second, which helps understand the importance of total rational impact rather than simple absolute unrejected volume.) (once postfix supports dcc i expect to see it change to 8000/10000, btw.)
Maybe there is no technical solution, of any value, possible (at the system / DoS level, not talking about individual approaches like whitelisting.)
I'm quite serious.
i know you are, but i think the better statement would be "there is not going to be a single long term solution, either technical or nontechnical." we're going to see a lot of point solutions, as each participant seeks to shift the costs of handling unwanted e-mail away from themselves.
My point is that I think we really need to start focusing on solutions which aren't primarily or solely technical.
the folks at http://spam.abuse.net/ and http://www.cauce.org/ and even http://www.spamcon.org/ would be alarmed to hear you say that they've been focused on purely technical solutions all these years.