So, what we need to do is learn from that experience. 8.5 years later
support for 3597 is a very reasonable thing to expect, and with AAAA,
DNSSEC, etc. we're well past the era where hidebound DNS software is an
acceptable operational model.
There are indeed very few current DNS servers that can't be persuaded
to serve up arbitrary record types, but as we've been saying over and
over, that's not the problem.
The problem is provisioning software. We weenies can stuff anything
into our DNS servers we want, because we use vi and emacs and (in my
case) custom perl scripts. For the other 99.5% of the world, what
they can put in their DNS zones is limited to whatever the web
provisioning software at their registrar or ISP or web host supports,
and I challenge you to find any that supports SPF records.
Ietf mailing list