post...@ptld.com:
> > Domain alignment is essential to DMARC. DMARC always refers to the
> > From header domain. SPF validates the envelope sender (MailFrom)
> > domain. DKIM can validate any domain, even one not used anywhere else
> > in the message. For DMARC to succeed, the From header domain must
> > align with a domain whose validation mechanism succeeds.
>
> All of that makes sense. Anyone know why a sizeable percentage of emails
> from the dovecot mailing list fail dmarc? Is dovecot doing something
> wrong or is it users with improperly setup dkim keys? Because it seems
> like mail from the postfix mailing list always pass dmarc.
The Postfix list uses Majordomo. It adds Sender and List- headers,
As long as the original DKIM signature did not cover such headers,
the signature will continue to validate.
Wietse
