Hello, On Wed, 8 Apr 2020, Mark Wielaard wrote:
> On Tue, 2020-04-07 at 11:53 +0200, Florian Weimer via Overseers wrote: > > Gmail can drop mail for any reason. It's totally opaque, so it's a > > poor benchmark for any mailing list configuration changes because it's > > very hard to tell if a particular change is effective or not. > > > > Many mailing lists have *not* made such changes and continue to work > > just fine in the face of restrictive DMARC sender policies and > > enforcement at the recipient. > > > > In general, mail drop rates due to DMARC seem to increase in these two > > cases if the original From: header is preserved: > > > > * The sender (i.e., the domain mentioned in the From: header) > > publishes a restrictive DMARC policy and the mailing list strips the > > DKIM signature. > > > > * The sender signs parts of the message that the mailing list alters, > > and the mailing list does not strip the DKIM signature. > > > > If neither scenario applies, it's safe to pass through the message > > without munging. The mailing list software can detect this and > > restricting the From: header munging to those cases. > > > > I doubt Mailman 2.x can do this, so it is simply a poor choice as > > mailing list software at this point. > > Earlier versions of Mainman2 had some issues which might accidentally > change some headers. But the latest fixes make this possible. It is how > the FSF handles DMARC for various GNU mailinglists (by NOT modifying the > headers and body and passing through the DKIM signatures): > https://lists.gnu.org/archive/html/savannah-hackers-public/2019-06/msg00018.html Oh, that would be nice to have at sourceware.org. Please? :-) Ciao, Michael.
