> However, I have since abandoned and now even oppose the idea for a
> variety of reasons. These include the total failure of the several
> serious attempts to build an online money "micropayment" system

My scheme of trusted SMTP servers has no need for "micropayment". It
is not a charge per email, but rather a flat fee. Flat-rate DSL
connections exist; there is no need for "micropayments" per byte
or whatever. Similar concept.

> or
> other such infrastructure, and the almost impossible problems raised
> by any solution that needs new software at both sender and
> recipient.

No new software is needed.

> There are also free speech concerns.

I think that spam is not covered by free speech. ANYONE can still
send me an email under my system. However, I can reject it (if I
choose to; no-one forces me to) if it doesn't come from a trusted
server.

I think the trusted SMTP server scheme is much closer to your
trusted and unknown areas of the net than to your old estamps idea.
The cost (paying for the use of a trusted SMTP server) is a red
herring; it's really no different than paying for the internet
connection itself.