Re: [dmarc-ietf] DMARC ATPS Interop Note

[Douglas Otis <[e-mail]>]

On 5/9/15 8:07 AM, Murray S. Kucherawy wrote:
> On Sat, May 9, 2015 at 2:00 AM, Stephen J. Turnbull <[e-mail]>
> wrote:
>
>>  > Agreed again.  And as Terry has said and I think we can infer about
>>  > other large operators, it's incorrect to assume (and plain wrong to
>>  > assert) that this is an easy problem for them to solve in a
>>  > reliable way.
>>
>> Please define "reliable."  I gather you all think that missing some
>> mailing lists is a bigger problem than missing all of them, but for
>> the life of me, I cannot see why.
> I'm having trouble coming up with a heuristic that is even certain to grab
> "most" of them.

Dear Murray,

I'll create another DKIM extension to implement required
replication of header fields for third-party domains.  This
can be implemented by just those originating the messages
AND those implementing DMARC.  Most mailing lists should not
be impacted by the required header field approach, but this
should remove a presumed need for yet another DKIM
signature.  I will have the DKIM extension draft published
shortly. 

Also, you seem to dismiss a sizable corpus of DMARC feedback
that can be verified by recent outbound logs. Of course only
a DMARC domain imposing restrictive policies will have any
need to implement this scheme which they should also see as
their obligation if they have any desire to have their
policy requests used.  That said, the update to DKIM should
be able to simplify what is contained in TPA-Label.

Together, these methods only require implementation by the
sender AND those imposing restrictive DMARC policy.

Regards,
Douglas Otis