On Wed, Apr 16, 2014 at 10:34:23AM -0400, Jan Wieck wrote:
> addresses possible again. I am in favor of following exactly the
> same route and block all mail from @yahoo.com (and other DMARC
> participating ISPs) on our lists.

Just to be clear, it's not "DMARC participating", but a particular
profile of DMARC.  This particular DMARC setting is well-known to be
inappropriate for this kind of mail use.  That doesn't mean that all
uses of DMARC would have the same results.  Google, for instance, is a
big proponent and user of DMARC, and yet they have managed not to
break mailing lists.

A
-- 
Andrew Sullivan
ajs at crankycanuck.ca