On Oct 7, 2022, at 15:08, Wietse Venema <wie...@porcupine.org> wrote:
> Envelope or header?
On 07.10.22 18:59, Dan Mahoney wrote:
> Header, I think. If you mean the bit in the <dmaho...@foo.org> part of the
> To: line. DKIM and DMARC are looking at typically from, to, cc, (other
> headers too, but less likely to be rewritten).
I think this is solving the problem at the wrong end: namely, when
your users receive email.
Instead I think it should be solved at the point where your users
send email.
If you canonicalize your user's email addresses in the email messages
that they send (i.e. canonicalize before DKIM signing outbound
mail), then the responses to those messages will use their canonical
address. Over time, users will give out their canonical email
addresses to their relations because that is what they mostly see.
Wietse
