Re: [dmarc-ietf] PSD flag vs Version bump

[John R Levine <[e-mail]>]

> Why not say "SHOULD use tree walk", and then document, as explanation
> for "SHOULD" instead of "MUST", non-normative reasons why you might
> not?

I don't think that will fly with the VLMPs.  The mandatory PSD seems 
relatively easy to implement, just add it to the template you use for 
everything.

R's,
John

> On Sat, Jun 10, 2023 at 5:05 PM John Levine <[e-mail]> wrote:
>>
>> It appears that Scott Kitterman  <[e-mail]> said:
>>>
>>> What's the incentive that any existing DMARC users (senders or receivers) would have to invest additional resources in another email
>>> authentication protocol?
>>
>> We have two of the largest mail operators in the world saying that if
>> they can't tell which org domain scheme domain expects, they won't
>> implement the tree walk. We have to do something or we are wasting our
>> time.
>>
>> So how about this: in the tree walk, you look for DMARC records that
>> have an explicit psd=y/n/u tag. If you find at least one record with a
>> tag, you use the new scheme. If you find no records with a tag, you
>> fall back to the old scheme. I think this will let people do
>> everything they can do with the current tree walk, while being
>> backward compatible. If you want a domain to be an org domain you put
>> psd=n, if you want the tree walk to skip it and keep looking, you put
>> psd=u, and if it's one of the 0.001% of domains that actually is a
>> PSD, you put psd=y.
>>
>> We already added DiscoveryType to the aggregate report schema so we
>> are OK there.
>>
>> R's,
>> John
>>
>> PS: Whether we say people SHOULD NOT use SPF is a separate issue.

Regards,
John Levine, [e-mail], Taughannock Networks, Trumansburg NY
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