On Tue 02/Apr/2024 10:11:08 +0200 Emanuel Schorsch wrote:
Just to add some specifics, since August of 2023 we've gone from seeing ~100 ARC sealers of meaningful volume to over 300 as of yesterday. It is extremely important in our experience to have standard ways of identifying indirect flows. ListId headers and ReceivedHeaders are the bare minimum for MailingLists today, but those are both easily spoofable and ARC provides a much safer approach to standardizing that indirect flow identification problem.
It would be desirable to have a means to set up indirect mail flows so as to make ARC sealers trusted even when they are low-volume senders. It would also be nice to know, for DMARC-triggered bounces, whether any ARC seal also failed to verify rather than not being trusted. In the latter case, if a procedure exists to register ARC sealers, the 5xx response would be a good place to advertise it.
Best Ale -- _______________________________________________ dmarc mailing list dmarc@ietf.org https://www.ietf.org/mailman/listinfo/dmarc
