MTA mints tokens

Hi hashcash!

If MTAs added tokens to emails this could allow sooner deployment of 
hashcash while users still use non hashcash MUAs. Small MTAs can 
take the load while bigger systems may need additional computing 
resources. A dedicated minter server cost roughly 0.06 cent/minute 
or 18 minutes/cent. I guess most people would not mind paying 0.06 
or even 1 cent per email so this cost can be included in the ISP 
costs. To avoid spammers abusing this service the number of 
emails/day can be limited. Heavy email users have to pay extra or 
make hashcash themselves. Occasionally exceeding the limit may get 
emails delayed until token computing power get's available at off 
peak hours. Minting can also be ordered by email priority.

Moving token creation to a permanently online MTA probably also 
allows for convenient negotiation of required token bits. This could 
be part of SMTP.

Talking about wasting resources reminds me I'd rather like to pay 
real money to the receipient than for wasted resources. But 
anonymous ecash may be difficult in the days of big brother.

Bernhard

[1] A server may cost 50000 cent with a lifetime of 3 years makes 
50000/(3*365*24*60)=0.03 cent/minute. Electricity costs: 15 c/kWh / 
0.1 kW / 60 minutes/h = 0.025 c/100 W/minute. So we are at 0.06 
c/minute or 18 minutes/c. Double/halve that for systems which idle 
half the time.