On Saturday, April 8, 2023 10:24:09 AM EDT John Levine wrote: > It appears that Scott Kitterman <skl...@kitterman.com> said: > >I think you have gotten yourself side tracked. > > > >The problem with DMARC and mailing lists is that receivers doing DMARC > >checks can't (absent a list of mailing lists) reliably distinguish DMARC > >fail due to normal mailing list processing and DMARC fail due to abusive > >behavior. > Even a list of mailing lists won't do it. One of the reasons ARC is > useful is that it lets recipients look back through the list manager > and recognize mail that was abusive before it hit the mailing list.
OK. A list is necessary, but not sufficient. ARC still needs some external mechanism to determine when to apply it. It can't be used to override DMARC results for all mail flows, only the ones that you have sufficient trust in not to lie in their ARC header fields (e.g. well behaved mailing list operators). Scott K _______________________________________________ dmarc mailing list dmarc@ietf.org https://www.ietf.org/mailman/listinfo/dmarc