Re: [dmarc-ietf] Signaling MLMs

["Murray S. Kucherawy" <[e-mail]>]

On Thu, Apr 13, 2023 at 8:14 AM Barry Leiba <[e-mail]> wrote:

> There's no need for a signal here: the MLM can simply check the
> sending domain's DMARC policy when a new post comes in, and
> preemptively reject it if the policy is "reject".  The IETF considered
> doing that and ruled it out because it would mean that users with
> yahoo.com addresses (and others) could then not participate in IETF
> mailing lists without changing addresses.  I think that was the wrong
> decision, but we decided on the ugly "from" alteration instead.
>

My idea is based on two assumptions:

(1) MLMs don't necessarily want to start doing DNS queries.  They operate
just fine never touching the DNS today; this is a new dependency and bunch
of stuff they have to learn to apply and suppot.

(2) An author domain can decide to affix this at its discretion, so it has
some say in which out-flows are subjected to this "do not modify"
constraint.  Of course, that discretion can lead to other problems, such as
the author domain not affixing it when it should, or vice versa.

As for the IETF, if this WG comes out with contrary advice to that
decision, we (the IETF) would have to reconsider.  It's an ugly question
either way.

I still think that outright refusal of posts from p=reject domains is
> a good approach and I wish it were used more, but most MLMs that are
> willing to put in a change to address this seems to prefer not to
> punish the sending domains users for the excesses of the domain
> management.
>

I think if the outcome is that we decide we don't want to do this, this
discussion would be good to capture in the document to indicate what we
considered and discarded.

-MSK, participating