Re: Enabling DMARC workaround code for all IETF/IRTF mailing lists

[Brandon Long <[e-mail]>]

On Sun, May 13, 2018 at 4:50 AM Alessandro Vesely <[e-mail]> wrote:

> Just a couple of notes:
>
> On Fri 11/May/2018 14:00:15 +0200 Alexey Melnikov wrote:
> >
> > Below are some technical details on how the email address rewriting
> workaround is going to work:
> >
> > Emails from domains that don't have a p=reject DMARC setting are not
> going to be affected in any way.
> >
> > For emails from p=reject domains:
>
> Some put p=reject; pct=0; for the sole purpose of having From: rewritten.
> The
> principle of least surprise would suggest to apply rewriting uniformly.
>
> > - The From header field of such emails will be rewritten to be under
> > @dmarc.ietf.org domain (which will have a p=none policy). For example,
> > "[e-mail]" email address would become
> > "alexey=[e-mail]". The original From header field
> will
> > be preserved in the X-Original-From header field, which can be used for
> > automatic message processing by Sieve and Mail User Agents.
> Besides encoding, the semantic of alexey=[e-mail] will
> never be clear, even to those familiar with DMARC.  My experience after
> replying "all" on one of those messages was not what I expected, and I
> couldn't
> tell if that was a bug[*].  How about just appending the original address
> to
> Reply-To[**]: and keep the From: address as simple as [e-mail]?
>

One of the benefits for having a per-sender unique from address to rewrite
to, is that it plays better with email clients who might otherwise get
confused that all of the messages are from the same person.  For example,
Gmail doesn't display quite right the "authors" of a thread if they're all
from the mailing list.  Other address book software might "learn" the name
of a list, or add the list address to the name or other confusion.

That said, using unique rewrites does open up a different can of worms in
terms of spam forwarding and different types of address book issues.

A client could use the List-ID header matching the From header to be
smarter, it's a bit harder if every mailing list provider used a different
rewriting scheme
to be smarter.

Which works better in practice, I don't know.  Adding Reply-To, even if the
from keeps the per-user rewriting, is probably a good idea.

Brandon