John, The difference from DKIM1 (your current times comparison) is the i= counter. In DKIM1 a signature says “we signed this.” In DKIM2 i=1 is also a chain position assertion: the verifier is told this is the first hop. A message with References and In-Reply-To headers is not incongruous with a DKIM1 signature; in DKIM2 a verifier following chain logic has legitimate grounds to ask why a message presenting as first-hop has headers that suggest otherwise. That question is new. Leaving addressing this newly created DKIM2 concern to operator judgment and the inconsistent implementations it will spawn is what the BCP note is trying to avoid.
William From: John Levine <[email protected]> To: <[email protected]> Cc: <[email protected]> Date: Mon, 12 Oct 2026 13:47:16 -0600 Subject: [Ietf-dkim] Re: BCP: operator note on header size limits and Message-Instance growth > It appears that William Weiner <[email protected]> said: > >A re-originating intermediary appears to the receiver as any other > >originating signer: a chain beginning at i=1 under its own domain, > >with no prior chain. A message re-originated in this way may > >nonetheless carry thread and context headers - References, In-Reply-To, > >Reply-To, List-Id and similar - that suggest the message is a reply > >or was distributed through a list server. .... > > Well, yes, but every message anyone sends in response to list mail, > such as this one, has similar headers. > > I still see nothing special about reoriginated mail and see no reason > to say anything about it in any of our drafts. If you have a good > reputation, people will deliver your mail. > > Hypothetically spammers might put fake headers on mail to make it look > like it's not from where it's really from, but there's nothing new > about that either. Thirty years ago I was tweaking mail filters to > ignore fake Received headers so I could send complaints > > R's, > John > _______________________________________________ > Ietf-dkim mailing list -- [email protected] > To unsubscribe send an email to [email protected] > _______________________________________________ Ietf-dkim mailing list -- [email protected] To unsubscribe send an email to [email protected]
