Re: sender rewriting scheme

On Mon, Oct 06, 2003 at 02:28:25PM -0400, Meng Weng Wong wrote:
> Is there a better solution to the .forward problem than sender rewriting?
> 
> Any kind of designated sender scheme will, in the worst case, break
> every .forward in existence.
> 
> In the worst case that means we need to patch every MTA in the world to
> do sender rewriting for .forwarding.
> 


The problem is that every spammer can just act as if it were a
forwarder.

If you want to solve that problem, you'll have to verify that 
the forwarder had not created the message, but actually received from
an authorized sender. This problem will be very difficult to solve
without cryptography. And it will be difficult with cryptography. It
will be difficult anyway. Patching every MTA might be the cheapest
solution. 

regards
Hadmut