Re: Who should set the Sender: header field?

--On Friday, December 17, 2021 13:18 +0100 Alessandro Vesely
<[email protected]> wrote:

> On Fri 17/Dec/2021 04:10:43 +0100 John C Klensin wrote:
>...
>> I would favor a statement in the proposed A/S about this (or
>> any similar feature) warning people that the feature is not
>> widely supported, that it cannot be expected to work
>> universally in an interoperable way, may result in mail being
>> bounced and/or lost, and hence should probably be avoided
>> unless the sender knows it will be handled properly at the
>> recipient end.  I'd be hesitant about removing the
>> construction from 5322bis entirely, but could be convinced.
>...

> Since G say they banned multi-mailbox From: after DMARC (with
> no statement about how/if it worked before), perhaps if we
> rewrite DMARC so as to not preclude the authentication of that
> kind of messages, they might eventually restore the
> functionality.  Authenticating the sender of a multi-mailbox
> From: message does not suggest that its end-to-end flow is
> likely to work, but neither denies it.

Please take that comment/ suggestion to the DMARC WG [1].  At
least IMO, discussion on this list is not likely to be helpful
in shaping DMARC/ARC.

    john


[1] https://datatracker.ietf.org/wg/dmarc/