[Mimedefang] DMARC pessimism (was Re: ADMINISTRIVIA: Yahoo users may not post to this mailing list)

[David F. Skoll]

On Wed, 23 Apr 2014 10:32:48 -0400
Joseph Brennan <brennan at columbia.edu> wrote:

> The madness has spread to AOL effective yesterday 4/22.

Ah well.  The intersection of "AOL users" and "MIMEDefang members"
is empty.  This is not entirely unexpected. :)

These moves, by the way, will have the effect of rendering DMARC completely
useless.  Mailing-list owners will change the From: header to
look something like:

From: "poster at yahoo.com" <address at listdomain.net>

Users will see "poster at yahoo.com" in their MUA.  They will see a
successful DMARC pass.  The concern I raised at
http://www.dmarc.org/pipermail/dmarc-discuss/2012-February/000189.html
will continue to go unaddressed.  And DMARC will fade into the sunset
as yet another failed attempt to bolt some sort of end-to-end identity
validation on top of SMTP. :(

Regards,

David.