On Dec 18, 2016, at 12:05 PM, Dave Crocker <dhc(_at_)dcrocker(_dot_)net>
wrote:
I believe some mailing lists have adjusted to detection of DMARC (maybe just
when p=reject?) for a given author by making author From: field changes
/only/ for such authors. They don't make changes when mail is from non-DMARC
authors.
The "postfix-users" adjusted to avoid breaking DKIM upstream
signatures, well before DMARC, by avoiding making any changes
to the message body and (most) headers.
At the cost of not adding subject tags or message footers,
the list does not encounter any DMARC issues. The only
message modification is addition of "List-" headers and
and a "Sender:" header.
Perhaps that's not a viable option for IETF lists. FWIW the
subject tags could be added by upstream authors as a matter
of courtesy. Indeed ietf(_at_)ietf(_dot_)org has no footers or subject
tags, and would be expected to not fail DMARC after forwarding.
--
Viktor.