To me, the approach you advocate is something like saying "do away with any centralized law enforcement, force everyone to carry guns, and if anyone suspects

else is committing a crime, they are obliged to shoot them." I believe

spam at its source is far easier than blocking it at every possible destination. The less parties involved in blocking the spam, the higher the probability

that someone that blocking that the spam

will be successfully blocked.

To do this you need to form a police force and a judiciary. Neither are possible in the absence of an organized society. The first step is for some of the larger senders/receivers of email to sit down around a table and form an email services consortium that can set "best current practice" standards and police those standards. This is something that network operators can do. --Michael Dillon