On Tue, Aug 3, 2021 at 3:59 PM Dave Crocker <[email protected]> wrote:
> On 8/3/2021 12:54 PM, Todd Herr wrote: > > 2. Define a tag named "t", in a fashion somewhat similar to the t= tag > > available for DKIM public key records, as follows: > > A reasonable suggestion, based on the extended discussion. > > I have a devil's advocate question, with two purposes. One is because I > really am interested in understanding this better. The second is > because it might prompt the additional of some explanatory text, to that > future readers of the spec will also understand this better: > > My question: what does this accomplish, of significant benefit, that > p=none does not? > To cite one example, "p=quarantine; pct=0" triggers rewriting of the "From:" header at some intermediaries (such as Google groups) where "p=none" does not. I cannot articulate how such rewriting helps a domain owner eventually move to a policy of p=quarantine or p=reject with no pct tag. That doesn't mean that I think it's not a useful setting on the journey from p=none to something stronger; it only means that I can't remember the particulars of the rewriting that takes place and how the domain owner can take advantage of information revealed by the rewriting in order to eventually remove the pct tag. It might be this: - p=none: I as a domain owner receive aggregate reports showing all mail that I originated (and obviously stuff I didn't), with some of my originated mail flowing through intermediaries - p=quarantine; pct=0: I as a domain owner receiving reports showing all mail that I originated except for mail that flowed through intermediaries that do From: header rewriting. I can then examine the differences in the reports, suss out which intermediaries aren't rewriting the From: header, and decide if I care enough about the volume I'm sending to those intermediaries to have it affect my decision to move to a stronger assessment policy. The above all pre-supposes that p=quarantine or p=reject will also cause those intermediaries that rewrite when they see pct=0 to rewrite when they don't. That may be a valid assumption, but I'd rely on someone with more knowledge of the state of play here to speak to the topic. -- *Todd Herr* | Technical Director, Standards and Ecosystem *e:* [email protected] *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.
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