> On Dec 18, 2016, at 12:05 PM, Dave Crocker <dhc@xxxxxxxxxxxx> 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@xxxxxxxx has no footers or subject tags, and would be expected to not fail DMARC after forwarding. -- Viktor.