ietf-822
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Re: MTS transparency and anonymity

2005-02-28 07:57:20

On Mon, 28 Feb 2005, Keith Moore wrote:

I agree that it is wrong to reject null return paths altogether. However
your suggestion is incompatible with backscatter detection systems (such
as BATV or Signed Envelope Sender) which assume that null return paths are
only used for bounce messages.

those systems are operating on false assumptions.  it's never been the case
that <> was limited to bounce messages.

Yes. It'll be interesting to discover the extent of the interop problems :-)

I think we're going to have to tighten up the rules about null return
paths and bounces, because of the backscatter problem. If anyone has any
ideas for dealing with it that are better that BATV-alikes then I'm all
ears. Note that the other email authentication systems don't solve the
problem - or if they claim to do so they assume that email delivery is
single-hop and that malware does not retry and that everyone will deploy
the new technology, all of which are wrong.

Tony.
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