On 3/13/2017 10:03 AM, Carsten Bormann wrote:
(reason: 450 4.7.26 Service does not accept messages sent over IPv6
[2001:638:708:30c9::12] unless they pass either SPF or DKIM validation (message
not signed))
...
So they give their mail server an IPv6 address but then don’t accept certain
messages on that that they would happily accept over IPv4.
Email abuse across the open Internet remains impressively high.
Typically above 90% of traffic. There is a very strong undercurrent of
desire amongst some email-receiving operators to require all mail to be
authenticated, in order to facilitate accountability for email streams.
That is, to have SPF and/or DKIM tests succeed.
Some of them have the view that the transition to IPv6 is a place to
impose this stringent policy.
In one of the anti-abuse organizations, I've tried to point out the
problems with imposing policy changes based on transport -- independent
of whether the policy change is a good idea -- but to no avail.
d/
--
Dave Crocker
Brandenburg InternetWorking
bbiw.net