Re: DMARC from the perspective of the listadmin of a bunch of SMALL community lists

[Mark Andrews <[e-mail]>]

In message <[e-mail]>, Miles Fidelman writes:
> Theodore Ts'o wrote:
> > On Sat, Apr 12, 2014 at 03:56:14PM -0400, Miles Fidelman wrote:
> >> We (really I) support perhaps 2 dozen small email lists, for a bunch of
> >> community groups (PTOs, churches, neighborhood groups) - mostly the legacy
> >> of previously running a small hosting firm, and still having the machines
> >> sitting in a data center.  The kinds of groups with lots of non-technical
> >> users who have email accounts on Yahoo, hotmail, AOL, Comcast, and such.
> >> The lists range in size from tiny (5 person boards of directors) to maybe
> >> 1000 (high school parents).
> > Why don't you just respond by sending an e-mail to each of the
> > affected users, telling them that they will unfortunately no longer be
> > able to participate in the mailing list due to the choices of their
> > mail provider, and that if they want to continue to receiving e-mail,
> > to consider setting up new e-mail account with some other provider
> > such as gmail -- and then cc [e-mail] on the message.
> >
> > That's how I plan to deal with things....
> >
> > 					- Ted
> 
> Well, it's certainly attractive, if time consuming.  2000 or so people, 
> or 24 or so list messages, plus dealing with all the folks who ask me to 
> personally unsubscribe one address, and add their new one.  Probably 
> less painful to patch the list manager to re-write the From address of 
> incoming mail (which is what seems to be where a lot of people are going).
> 
> As to them impact on Yahoo - I expect they'd ignore it.  On the other 
> hand, I'm starting to wonder about suing them for damages and creating a 
> public nuisance. :-)  [yes, I'm feeling a little vindictive right now.]

Just reject any email with a DMARC "p=reject" qualifier destined
to a email list at the SMTP level that doesn't include you as a
valid sender.

5.x.x DMARC p=reject not compatible with email sent to a mailing list

What Yahoo is doing is anti-social.  It is forcing people who don't
want to be involved in DMARC to particate to some level as they are
getting all the bounces from Yahoo's idiocy.

Alterntively reject all @yahoo.com email until the DMARC record is
changed.  If Yahoo want to apply presure to people to support DMARC
by changing their software, email list operators can apply presure
back when they deliberately do something stupid like this.

Mark

> Sigh...
> 
> Miles
> 
> -- 
> In theory, there is no difference between theory and practice.
> In practice, there is.   .... Yogi Berra
> 
-- 
Mark Andrews, ISC
1 Seymour St., Dundas Valley, NSW 2117, Australia
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