Has someone contacted any big ISPs to see whether they are willing
to implement MTAmark? If none of the ISPs that host spam zombies
(from which 80% of the spam originates according to some recent
report) right now will participate then it seems the proposal won't
be useful. AFAIK several big ISPs have been approached and have
not shown any interest.
I am talking to certain ISPs about technology that would assist in
tracking down zombies that is similar to MTAMARK. I have had some
very favorable responses.
I am unable to support MTAMARK because the present proposal is
incoherent. If I control an IP address I can block port 25, so why
would anyone implement a rube goldberg scheme that allows me
to say 'i should have blocked port 25 but did not'?
Ask the ISPs to do something coherent such as using the reverse
DNS to advertise contact addresses, abuse notification mechanisms,
the characteristics of the IP connection, that is tractable and
I get a good response.