Yes, I am talking about inbound policies. Mailing list damage happens when inbound filters block a harmless message that the user wants. So the best fix is for the inbound filters to acknowledge that they live in an environment with imperfect information.
The Sender can only ensure that all of his mail is signed. He cannot ensure that no other legitimate source will impersonate on behalf of a single user, or that no legitimate intermediary will alter content during forwarding. The recipient evaluator has the job of delivering what its users need and blocking what can harm them or don't want. Senders cannot fix evaluators that do that poorly. Google says they cannot do conditional processing of p=reject, but they don't block on DMARC fail at all. They make up for that limitation by having other spam filtering logic that is pretty impressive. My Gmail accounts have very few problems with either spam getting through or wanted messages getting blocked. I don't have the same content filtering sophistication, so I have ramped up my sender filtering. Doug Foster On Tue, Apr 11, 2023, 11:15 AM Neil Anuskiewicz <[email protected]> wrote: > > > > On Apr 11, 2023, at 4:29 AM, Douglas Foster < > [email protected]> wrote: > > > > > > Neil, I am slowly embracing the position of the Mailing List advocates. > > > > If mailing lists and all other exceptional situations could be > eliminated, evaluators could mindlessly apply a rule to "block on fail when > p=reject". Similarly, if all evaluators would implement reliable > mechanisms for domain members to request and obtain exceptions for mailing > lists and other exceptional traffic, then domain owners could publish > p=reject as soon as all of their traffic had signatures. Unfortunately, we > have a reality that some highly valued traffic arrives without > authentication, and some evaluators do not provide an effective exception > process. This conundrum is aggravated by filtering products that do not > provide administrators with sufficient exception configuration options. > I am content with language that documents this conundrum. > > > > The Internet will always be an environment of imperfect information, so > the only viable filtering scheme is one which expects and allows for > exceptions. Additionally, my defenses against impersonation should not be > dependent on the domain owner's policy statement. Any allowed message is > implicitly assumed to be free of impersonation, but assumptions are > dangerous. It is my job to replace guesswork with certainty based on > research. As indicated earlier, this can be done. Using DMARC, SPF, and > local policy, I am at 100% verified for MailFrom, and 97% verified for > From. Mailing lists have nothing to fear from my filtering and I have > nothing to fear from p=none. > > > > In short, we need smarter filtering. > > > > Doug Foster > > Mr. Foster, you seem (though I could be wrong) to be talking about inbound > where you have complete control but for policies set in domains sending > outbound, how would filters resolve the problem? We have little control > over outbound. Threat actors will Phish wherever the phishing is good. > > I guess I was hoping that security could be the top priority but it’s > likely naïveté. I can see the I trade offs. You piss off too many people > and you end up with a standard nobody wants to use. > > Neil
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