If the evaluator domain might forward an unmunged message, the domain needs
to re-mung at the domain exit MTA.   How much of an obstacle will this be?

On Tue, Oct 12, 2021, 6:06 AM Alessandro Vesely <[email protected]> wrote:

> From: rewriting confers 100% deliverability on messages, but has a bad
> impact
> on the end user.
>
> If we consider collaborative solutions, we see that, because of their very
> nature, they cannot cover all cases.  So, it is safer to look for
> collaborative
> solutions that allow unmunging than to solutions that avoid munging in the
> first place.  Indeed, in the former case the risk is to deliver a munged
> message, while in the latter one the risk is to either not deliver or not
> to
> implement DMARC.
>
> Even ARC can be turned into a method to unmunge.  It requires
> collaboration
> between MLM and receiver.  My unmunging method requires cooperation
> between
> author's domain, MLM, and receiver.  Whitelisting can be done unilaterally
> by
> receivers, who can restore the original From: without validating the
> author's
> domain signature, just because they trust the MLM.  By collecting similar
> techniques, we might be able to cover almost all cases while still
> ensuring
> deliverability.
>
>
> Best
> Ale
>
>
>
> On Tue 12/Oct/2021 04:40:12 +0200 Douglas Foster wrote:
> > Barry, you did a nice job of talking me off the ledge.
> >
> > If this is about helping list operators and message evaluators to
> > collaborate in a way that avoids From-Munging, I have no objections.
> >
> > Repeatedly, the topic has seemed to turn in directions that make the
> > evaluator appear irrelevant -- as if the Lists don't need to talk to
> them.
> >
> > The reality right now is that a lot of From-Munging is unnecessary
> because:
> > - many evaluators do not enforce DMARC
> > - some evaluators enforce DMARC but have made exceptions for active lists
> > - some other evaluators enforce DMARC and will make exceptions if asked
> to
> > do so by their users
> > This leaves a small group, like AOL, who enforce DMARC and yet are
> > unresponsive to their users.   This small group needs From-Munging, or
> > unmodified messages, or different email accounts for list participation.
> >
> > I claim, without proof, that many of the most vocal critics of
> From-Munging
> > are using domains that do not require From-Munging on incoming messages.
> >   In such cases, the DMARC-enforcing sender is not the real
> > problem, ignorance is.
> >
> > Once the list and the evaluator have agreed to collaborate, we have a
> bunch
> > of signalling options, including options that survive forwarding.   They
> > are mostly simple extensions of things we are already doing, much simpler
> > and more determinative than ARC.
> >
> > Doug Foster
> >
> >
> > .
> >
> >
> >
> >
> >
> >
> > On Mon, Oct 11, 2021 at 10:28 AM Barry Leiba <[email protected]>
> > wrote:
> >
> >> It's not that the IETF shouldn't be involved with advice on what
> >> mailing lists should do.  It's that if we should put out a BCP or a
> >> standard that says mailing lists MUST NOT alter messages that they
> >> forward, those who write mailing list software (and those who deploy
> >> it) will not listen.  That's where Scott's "we're not the police"
> >> statement comes in.
> >>
> >> For whatever it's worth, mailing lists have been behaving this way
> >> for, as others have said, decades, and it has been considered good
> >> practice and has been found useful.  Mailing lists add footers on
> >> messages, whether to advertise the list, to add disclaimers, or
> >> whatever.  They like it, and won't change.  Mailing lists add the list
> >> name to the Subject line because it makes it easier to create filters,
> >> and because it makes it easier for eyeballs to filter (for the vast
> >> majority of users who don't know and don't want to know how to create
> >> filters).  They like that too, and that, too, won't change.  We could
> >> advise change, but it would be wasted effort.
> >>
> >> In contrast, the mailing list folks are saying that it's DMARC that
> >> came later, that is being deployed incorrectly, and that must change.
> >> Clearly, those who find benefit from strict DMARC policies disagree,
> >> and they've said clearly that they won't change.  And again, we're not
> >> the police.  We could put, in the standards track version of DMARC,
> >> that p=reject MUST be used ONLY for transactional mail, which MUST be
> >> isolated from mail that might go to mailing lists (worded better than
> >> that, but we all know what I mean here).  It would be shouting at the
> >> wind.
> >>
> >> We do the best we can to write reasonable standards and to give
> >> reasonable advice about using them.  We can identify problems and
> >> write our best advice about how to avoid/mitigate them.  Beyond
> >> that....
> >>
> >> Barry
> >>
> >> On Sun, Oct 10, 2021 at 1:13 PM Douglas Foster
> >> <[email protected]> wrote:
> >> >
> >> > This is disappointing and problematic.
> >> >
> >> > So, AOL publishes a policy which says that they do not want their
> >> outbound messages altered in transit, and implements filtering which
> >> demonstrates that they do not want inbound messages modified in transit.
> >> >
> >> > In opposition, we have mailing lists that claim an unrestricted right
> to
> >> alter messages in transit.
> >> >
> >> > What is the justification for IETF to be involved with developing
> >> strategies to undermine AOL's interests in favor of a Mailing List's
> >> interests?   It is capricious and misleading for you to say that we are
> not
> >> being the Internet Police, because we are clearly taking sides.  If we
> are
> >> not the Police, then apparently we are the Internet Smuggling Cartel.
> >> This just looks wrong.
> >> >
> >> > Doug Foster
> >> >
> >> >
> >> >
> >> >
> >> > On Sat, Oct 9, 2021 at 6:09 PM Scott Kitterman <[email protected]>
> >> wrote:
> >> >>
> >> >> Technically it's pretty easy to set up a mailing list which doesn't
> >> modify the message in ways likely to make DKIM fail.  Almost no one
> bothers
> >> to do so despite pressures resulting from widespread use of DMARC
> p=reject.
> >> >>
> >> >> Operators do not need to justify anything to us.  We are not the
> >> internet police.
> >> >>
> >> >> For our purposes it's enough to know that they do and there's no
> >> evidence that it's likely to change.
> >> >>
> >> >> Scott K
> >> >>
> >> >> On October 9, 2021 7:39:36 PM UTC, Douglas Foster <
> >> [email protected]> wrote:
> >> >> >I would be pleased to see a document which explains why lists MUST
> or
> >> >> >SHOULD alter content.    After more than 2 years following this
> >> discussion,
> >> >> >no reason for this practice has ever been documented.
> >> >> >
> >> >> >Content changes would be easier to justify if subscribers granted
> >> >> >authorization to modify as part of the subscription process.   But
> >> there
> >> >> >was not informed consent when I joined this list, so I doubt that
> >> informed
> >> >> >consent occurs on other lists either.
> >> >> >
> >> >> >What if, after reviewing the SHOULD list, an organization says
> "That's
> >> >> >interesting but unconvincing.   Please send messages to our domain
> >> without
> >> >> >alteration?"   Are lists equipped to give participants what they
> want,
> >> or
> >> >> >not?
> >> >> >
> >> >> >Doug
> >> >> >
> >> >> >On Thu, Oct 7, 2021 at 9:58 AM Barry Leiba <[email protected]
> >
> >> wrote:
> >> >> >
> >> >> >> Just on one point, for us to consider:
> >> >> >>
> >> >> >> > Personally, I think mailing lists changing From has horrible UX
> >> and I
> >> >> >> don't
> >> >> >> > really think anyone disagrees.  It's only advantages are that
> it's
> >> >> >> relatively
> >> >> >> > easy to implement in a Mailing List Manager (MLM) and it solves
> the
> >> >> >> entire
> >> >> >> > DMARC problem for a specific mailing list without needing anyone
> >> else to
> >> >> >> change
> >> >> >> > anything.  I understand the appeal.
> >> >> >>
> >> >> >> I think Scott is right that we all agree that rewriting From
> >> mitigates
> >> >> >> problems that mailing lists have with DMARC, but at a significant
> >> cost
> >> >> >> in usability.
> >> >> >>
> >> >> >> I think it would be bad to publish From-rewriting as a standard.
> >> >> >>
> >> >> >> But here:  I think it is reasonable, perhaps advisable, to
> >> >> >> informationally document From-rewriting as a mechanism that is in
> >> use,
> >> >> >> and to include in that documentation a clear exposition of the
> >> >> >> problems that it causes.  Why not get those horrible UX issues
> down
> >> on
> >> >> >> paper so that when someone decides to deploy it they are better
> >> >> >> informed?  Perhaps we can lead people to take steps to reduce the
> UX
> >> >> >> challenges (for example, rewriting the way the IETF is doing it at
> >> >> >> least addresses the issue of knowing who sent the message, and
> how to
> >> >> >> reply to the actual sender, as compared to a rewrite directly to
> the
> >> >> >> mailing list address).
> >> >> >>
> >> >> >> Doesn't that make sense?
> >> >> >>
> >> >> >> Barry
> >> >> >>
> >> >> >> _______________________________________________
> >> >> >> dmarc mailing list
> >> >> >> [email protected]
> >> >> >> https://www.ietf.org/mailman/listinfo/dmarc
> >> >> >>
> >> >>
> >> >> _______________________________________________
> >> >> dmarc mailing list
> >> >> [email protected]
> >> >> https://www.ietf.org/mailman/listinfo/dmarc
> >> >
> >> > _______________________________________________
> >> > dmarc mailing list
> >> > [email protected]
> >> > https://www.ietf.org/mailman/listinfo/dmarc
> >>
> >
> >
> > _______________________________________________
> > dmarc mailing list
> > [email protected]
> > https://www.ietf.org/mailman/listinfo/dmarc
> >
>
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