Re: [ietf-smtp] mailing lists are complicated, was Email explained from first principles

[John Levine <[e-mail]>]

It appears that Alessandro Vesely  <[e-mail]> said:
>Mailing lists often do keep DKIM signatures intact.  They only alter the rest 
>of the message, but the transformations they do are stylized enough to allow to 
>revert them and verify the original signatures. ...

We've been around this barn a few times before. What you say may seem
true if you have only seen a few lists handled by a single list
package. In reality, I have seen lists add headers and footers, add,
delete, and reorganize MIME parts while changing the MIME boundary
strings, rewrite URLs in message bodies, and flatten HTML bodies into
text. There is no way to list all of the common changes, much less
describe how to reverse them.

In any event, whatever you might want to do by reviving DKIM signatures is already
handled by ARC, so it'd be a lot more productive to encourage ARC adoption than
to invent yet another half-hearted DMARC workaround.

R's,
John