Re: [dmarc-ietf] non-mailing list use case for differing header domains

[Ken O'Driscoll <[e-mail]>]

On 03/08/2020 01:43, Douglas E. Foster wrote:
>
> I am not sure what "Internet Scale" means to you.   Most of the major
> recipients have bulk mailer registration systems.   It does not
> guarantee whitelisting, but it tends to produce that effect.   I have
> had occasion to register with most of them.   So "does not scale" is
> not obvious to me.

This is not correct. In the past some large providers did offer such
lists but these days most have moved away from that model for various
reasons. You'll still find someone offering such as service, and
pay-to-play is a thing too but none of this is a) widespread and b)
based on any type of standard - it's all proprietary. The same goes for
sender certification services such as ReturnPath.

"Internet Scale" means being able to scale to internet level of usage
and platform interoperability.  TCP/IP and DNS are good examples. Data
(e.g. lists of approved senders) maintained internally by individual
organisations can't scale to that level for the same reason that
organisations siloing their own DNS and routing information wouldn't
work. Interoperability.

Organisations publishing information (e.g. an SPF record) in their DNS
zone works because it's based on an existing internet scale
interoperable platform. While the "heavy lifting" of interpreting the
SPF record might be undertaken by a variety of different software and
system platforms, the mechanism is standardised based on the RFC. Again,
interoperability.

Ken.