headers in email

[Gregory Maxwell]

On 10/8/07, Michael_google gmail_Gersten <keybounce at gmail.com> wrote:
> On 10/6/07, Chris Jacobs <ctjacobs at xs4all.nl> wrote:
> > When email is remailed via TOR is it possible to add a header with a contact address for complaints,
> > like in cypherpunk remailers?
> Hmm. Technically, yes.
> To do so, you have to run a MITM node that intercepts traffic, looks
> at it, decides to modify it, and then alters the traffic being sent
> over it.
> That's the sort of thing that I think is considered a "bad thing".

There are nodes with open port 25 outbound?  I can't connect to port
25 via tor at the moment.

The better way(tm) to do this would be to just run an open SMTP server
as a hidden service, and run spam filtering, hashacash proof-of-work
challenge, whatever anti-abuse stuff you want, along with header
munging and striping, ... and advertise this server for people to set
their SMTP out to...

Then you don't have to feel bad about running a MITM node, and you
might manage to stay up for more than a few minutes before being used
to spam and getting blocked by every mail server on the planet. ;)

On this subject, it would be pretty interesting if the hidden node
support supported a client proof-of-work with server specified
difficulty in order to open a connection. If the SMTP server host were
setup to only allow one mail per connection the server could have POW
based abuse mitigation without special client software.