"Chris" == Chris Haynes <chris(_at_)harvington(_dot_)org(_dot_)uk> writes:
Chris> No, it does not.
Chris> I was pointing out that:
Chris> 1) Sender-ID makes the backscatter problem worse,
Chris> 2) SPF can in many cases make it better, but never worse.
Really? draft-mengwong-spf-01 permits rejection of a message with a
550 reply code if the SPF check fails, and that's what most
implementations seem to do.
If you reject an SMTP transaction due to an SPF failure, then the
up-stream MTA is likely to generate a bounce to a forged address.
As far as I can see, all MARID schemes are likely to increase
backscatter. In fact, anything that cause more mail to be SMTP
rejected will increase backscatter.
-roy