Re: [dmarc-ietf] Signaling forwarders, not just MLMs

[Todd Herr <[e-mail]>]

On Thu, Apr 13, 2023 at 11:21 AM Barry Leiba <[e-mail]>
wrote:

> > Anyone who does forwarding is damaged by DMARC because there are a lot of
> > people who do DMARC on the cheap with SPF only.
>
> This brings up another issue, I think: that there should also be
> stronger advice that using DKIM is critical to DMARC reliability, and
> using SPF only, without DKIM, is strongly NOT RECOMMENDED.
>
> I don't disagree.

How do we make the following text stronger?
5.5.2.
<https://www.ietf.org/archive/id/draft-ietf-dmarc-dmarcbis-27.html#section-5.5.2>Configure
Sending System for DKIM Signing Using an Aligned Domain
<https://www.ietf.org/archive/id/draft-ietf-dmarc-dmarcbis-27.html#name-configure-sending-system-fo>

While it is possible to secure a DMARC pass verdict based on only one of
SPF or DKIM, it is commonly accepted best practice to ensure that both
authentication mechanisms are in place to guard against failure of just one
of them.

This is particularly important because SPF will always fail in situations
where mail is sent to a forwarding address offered by a professional
society, school or other institution, where the address simply relays the
message to the recipient's current "real" address. Many recipients use such
addresses and with SPF alone and not DKIM, messages sent to such users will
always produce DMARC fail.
<https://www.ietf.org/archive/id/draft-ietf-dmarc-dmarcbis-27.html#section-5.5.2-2>

The Domain Owner SHOULD choose a DKIM-Signing domain (i.e., the d= domain
in the DKIM-Signature header) that aligns with the Author Domain.


-- 

*Todd Herr * | Technical Director, Standards and Ecosystem
*e:* [e-mail]
*m:* 703.220.4153

This email and all data transmitted with it contains confidential and/or
proprietary information intended solely for the use of individual(s)
authorized to receive it. If you are not an intended and authorized
recipient you are hereby notified of any use, disclosure, copying or
distribution of the information included in this transmission is prohibited
and may be unlawful. Please immediately notify the sender by replying to
this email and then delete it from your system.