Re: [exim] Generating hashcash for outgoing mail?

Tony Finch wrote:
>
> Hashcash is pointless. See the second paragraph on Richard Clayton's
> page about the paper he wrote with Ben Laurie: "Proof of work
> prooves not to work". Their result is intuitively obvious if you
> handwave about zombie farms, but they back it up with real-world
> numbers from Demon Internet.
>
> http://www.cl.cam.ac.uk/~rnc1/

Thanks for the link, Tony. I'm convinced.

This part of the paper was particularly depressing:

> We examined logging data from the large UK ISP for those customers
> who use the outbound "smarthost" (about 50,000 on this particular
> weekday). We excluded the one customer being actively exploited by a
> spammer and the four infected by a virus; and also the 145 with
> configuration problems that caused email to loop continuously.

- Marc