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

On Thu, Apr 13, 2023 at 12:19 PM Barry Leiba <barryleiba@computer.org>
wrote:

> Maybe just add a sentence to the end of the second paragraph:
>
>    The use of SPF alone, without DKIM, is strongly NOT RECOMMENDED.
>
> Barry
>

I think the opposite. Something along the lines of "Sending domains SHOULD
implement both SPF and DKIM to minimize breakage and non-delivery of mail.

Michael Hammer

>
>
> On Thu, Apr 13, 2023 at 12:04 PM Todd Herr <todd.herr@valimail.com> wrote:
>
>> On Thu, Apr 13, 2023 at 11:21 AM Barry Leiba <barryleiba@computer.org>
>> 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:* todd.herr@valimail.com
>> *m:* 703.220.4153
>>
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