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

[Barry Leiba <[e-mail]>]

Maybe just add a sentence to the end of the second paragraph:

   The use of SPF alone, without DKIM, is strongly NOT RECOMMENDED.

Barry


On Thu, Apr 13, 2023 at 12:04 PM Todd Herr <[e-mail]> wrote:

> 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
>
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