Yahoo DMARC breakage

[geoffk at geoffk.org (Geoffrey Keating)]

Andrew Sullivan <asullivan at dyn.com> writes:

> I think DMARC is mostly useful when used correctly.  There is no BCP
> yet...

There is, however, BCP167/RFC6377 covering DKIM and mailing lists.
Some relevant sections are 4.1 and 5.3:

4.1:
   ... site administrators wishing to
   employ ADSP with a "discardable" setting SHOULD separate the
   controlled mail stream warranting this handling from other mail
   streams that are less controlled, such as personal mail that transits
   MLMs [Mailing List Managers].  

5.3:
   At subscription time, an ADSP-aware MLM SHOULD check for a published
   ADSP record for the new subscriber's domain.  If the policy specifies
   "discardable", the MLM SHOULD disallow the subscription or present a
   warning...