On Sat 26/May/2018 06:55:55 +0200 Roland Turner via dmarc-discuss wrote: > On 25/05/18 19:00, Alessandro Vesely via dmarc-discuss wrote: > >> Wasn't this tried for SPF already? > > A whitelist of "I trust these guys to make exactly the same abuse-filtering > decisions that I'd make" and a whitelist of "I trust these guys not to lie in > ARC signing/sealing" are two very different things: > > * The former is somewhat imaginary and generally devolves to "I trust > these guys to filter abuse at or better than my ability to do so", > which essentially means a handful of big guys. > * The latter could readily include every existing mailing list > operator, and add new ones with minimal fuss.
Your points define ARC's scope very well. But what's big guys' role? Let me call /semantic mailbox providers/ those company or personal mail sites whose users have some kind of trust relationship with, e.g. because they work for the company, are postmaster's friends, or whatever. These providers can afford to let their users transparently perceive forwarders' filtering ability, be it naive SA deployment or sophisticated AI categorization. They may consider that users subscribing to mailing lists know what they do and let them enjoy or suffer its output as-is. "I trust these guys not to lie in From: rewriting" could be enough for them to whitelist DMARC breakage while keeping its anti-phishing feature, and dnswl.org would probably suffice to implement that, if agreeing on any single public whitelist were an acceptable means to make a protocol work. By contrast, big guys have so many users because they offer astounding functionalities, among which filtering is one of the most relevant. They need to filter forwarded messages in a manner 100% consistent with messages coming in directly. As you say, ARC will permit that by removing dependencies upon upstream filtering. I doubt anybody but big guys really needs that, but will be glad to be confuted. Best Ale -- _______________________________________________ dmarc-discuss mailing list dmarc-discuss@dmarc.org http://www.dmarc.org/mailman/listinfo/dmarc-discuss NOTE: Participating in this list means you agree to the DMARC Note Well terms (http://www.dmarc.org/note_well.html)
