Re: [dmarc-ietf] Charter improvements

["J. Trent Adams" <[e-mail]>]

Thanks, everyone, for their input on this thread (and to John for the
pointer how to get back to land when I blundered into the wrong stream).
Editing the proposed charter is a lot easier with this feedback.

>From what I can tell, the most important question needing to be answered
is whether or not revising the base DMARC specification is within scope
of the proposed work group. Following Russ's guidance, it seems that we
should start from the assumption that it's not in scope for now given
the fact that it's being sponsored by an AD as an Individual Submission.

Regardless of whether that's the right path, or not, let's explore it as
an option and see how the rest of the items identified in the proposed
charter play out. Then we can leverage the outcome of the conversation
to potentially revisit the fate of the base specification itself.

Given that guidance, here're the most obvious (and noncontroversial?)
items needing to be done to shore up the proposed charter:

* Correct the text regarding the current path of the specification.
* Tone down the "marketing puffery".
* Clarify how to address "backward compatibility" with the installed base.

I've already updated the description of the current path of the base
specification from "Independent Submission" to "Individual Submission",
so that's one down. I'll pull out my red pen on the other two topics and
see if I can make them more reasonable.

Skipping ahead. . . here're the items that have previously been proposed
as worth exploring in the setting of an IETF work group:

-----
* a mechanism for determining the organizational domain name based on an
arbitrary fully-qualified hostname
-----

If I'm not mistaken, the Apps Area WG has already expressed an interest
in this work. In that case, I believe that this WG would only need to
track that effort and ensure that its work addresses the use cases
required to support DMARC.

QUESTION: Given that it's an important topic, and there's no guarantee
that the other effort will result in an applicable solution, would it
still be reasonable to include a mention of this as worth exploration?
If so, it'd probably make sense to reference the other work as a
starting point to clarify we're not planning to spin up a competing
solution.

-----
* a mechanism for detecting abuse involving the <display-name> portion
of the RFC5322.From field
-----

This is an interesting item in that there have been some proposals from
contributors to the base DMARC specification to address this. The
proposals, as you can see, didn't make it through to a consensus and it
was suggested that they be brought to the broader community for
consideration. It's highly likely that through the WG process we're able
to identify a means by which this issue can be addressed.

QUESTION: Does it make sense for this proposed WG to explore how the
base specification can be extended to apply the same level of
"identifier alignment" to the <display-name> as is helping defend the
<address-spec>?

-----
* a mechanism for mitigating the effect of failures of DMARC policy when
a message transits a mailing list
-----

I recognize that there's definitely a counter-pressure against including
this topic as it seems to be a potentially quixotic quest. That being
said, even if we don't find the perfect solution, it does seem
reasonable to believe there is a way to provide something more than
nothing that does help in some meaningful way. I'm not presupposing a
solution, just that there have been a few possible options discussed at
the edges which are likely to be worth more rigorous exploration.

QUESTION: Is there value in a WG such as this exploring possible
solutions to this issue and developing guidance that would potentially
help improve the utility of the base DMARC specification?

-----
* support for the notion of transitive trust (i.e., "host X trusted the
sender of this message, and I trust X, so you should too")
-----

I see this as similar to the above, but potentially more broadly
applicable. One tweak I'd offer would be to replace ", so you should
too" with something like ", so you could choose to as well".

QUESTION: Is there value in a WG such as this exploring possible
solutions to this issue and developing guidance that would potentially
help improve the utility of the base DMARC specification?

-----
* more robust transport of reports
-----

After over a year of deployment, and the rise in support services
handling reports, many folks have suggested that it would be worth
exploring how to offer additional optional means of transport for
reports. The base DMARC specification provides for this, but it is an
area that was left to be extended by a group such as this.

QUESTION: Is this an area of exploration that is of enough interest to
include in the charter for this proposed work group?

Beyond those, the topics in the proposed "Using DMARC" document have
already proven useful in clarifying some options that aren't typically
included in a base specification. For example, here a few items that may
benefit from being specifically called out in the charter as worth
exploring:

* Identifier alignment configuration options
* Implementation decisions regarding "pct"
* Determining effective RUA sending frequency
* Leveraging policy caching
* Various options for integrating within an existing flow
* Defining a useful, common set of RUA reporting options
* When and how to use local policy override options

QUESTION: Do any items on this list seem to be worth specifically adding
to the proposed charter as examples of the type of work that would be
useful?

Finally, this list of potential work items was developed a while ago,
and it's likely additional possible areas of exploration have surfaced
since then. Are there any other substantive items that would be worth
adding to the list? Keeping in mind, of course, that our first cut will
be to assume that the base specification isn't in scope for now.

Once the dust settles a bit around these items, I'll take another whack
at the charter text to at least get it stable for now. Then we can
bubble up the bigger question and see if we can tackle that given the
input I've seen recently on other threads.

Thanks again,
Trent


On 7/2/13 10:50 PM, Matt Simerson wrote:
> On Jul 2, 2013, at 2:29 PM, "Rolf E. Sonneveld" <[e-mail]> wrote:
>
>>> In view of the large base of running DMARC
>>>  code, the group will avoid changes that would cause incompatible
>>>  changes to bits on the wire.
>> -1
>>
>> Granted, the installed base is large, but let's not ignore the other 40 percent of the Internet. IETF standards are standards for the _entire_ Internet community, not just ten or twenty of the largest companies in a specific area. The WG should not be bound by 'bits on the wire' in their review and possible comments on the standard. Otherwise the IETF is to a large extent degraded to the 'rubber stamp business' Scott mentioned.
>>
>> Don't get me wrong: the outcome of the discussions may well be that nothing will change on the wire and that'd be fine. But including this in the Charter as a precondition for the work to be done is wrong in my opinion.
> +1 to Rolf's -1. 
>
> I'm happy to see DMARC moving towards becoming a standard. Validation of incoming messages is a great feature. Reporting is more timely and structured than bounce messages. But for the vast majority of mail senders, DMARC is close to useless because of the forwarder / mailing list issue. 
>
> 	"DMARC policies are not appropriate for domains with users who send mail through mailing lists" --John R Levine
>
> 	"SMTP refusal to an unmapped-but-reliable forwarder is likely to cause list unsubscription." --Roland Turner
>
> The mailing list issue is intractable and also a huge implementation barrier that is barely documented. For legit domain owners (ie, not abusers) that wish to use DMARC to curtail phishing from their domains, they will need to choose between losing legit mail (DMARC + mailing lists) or not losing legit mail (no DMARC). 
>
> Most of the broader internet community does not have the resources to "map the exit IP addresses of well-behaved forwarders and ignore DMARC results for messages that come from those addresses."  As such, many domain owners will deploy DMARC, lose valid mail, and then reject the technology.
>
> While it may be kinda sorta true that DMARC "protects 60% of global consumer mailboxes," it seems to be  marketing puffery. While 60% of global mailboxes may have some form of DMARC validation, the number of legit domains that do and potentially *can* deploy DMARC records is absurdly low. 
>
> Other minor Issues such as report loops (DMARC reporters reporting each others DMARC reports to each other ad infinitum) are minor and have simple (but not yet documented) workarounds but could also be addressed technically, rather than requiring workaround documentation.
>
> Matt
>
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-- 
J. Trent Adams

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