Re: [dmarc-ietf] draft-crocker-dmarc-author-00 ?

[Steve Atkins <[e-mail]>]

On 12/08/2020 04:32, Dave Crocker wrote:
>
> Here's why I think it won't:  They already have From:.
>
> The real value in DMARC is not what is displayed to the end-user but 
> in having a required field that cites the originating domain name.  
> That doesn't change if there are additional fields that might or might 
> not mention the originating domain.

I think we disagree on the goal of DMARC. The entire point of DMARC is 
brand protection. Control over what is displayed to the user, not what's 
in any particular header. You could use it for other things, but that's 
what informed publishers of DMARC say they're using it for (sometimes 
phrased as "protection against phishing" but that too is all about 
what's displayed to the recipient).

If you display the contents of Author to the user, then DMARC publishers 
will want to control that.

If MUAs will display the contents of the Author: header where the From: 
header is now then draft-crocker-dmarc-author-00 effectively moves what 
used to be Sender: header to the From: header and what used to be the 
From: header to the Author: header.

You could achieve exactly the same result, with much less deployment 
effort, by updating DMARC to enforce the Sender header and leaving MUAs 
displaying the From: header. That wouldn't be acceptable to anyone who 
wants to publish DMARC, so the Author: proposal won't be either.

Cheers,
   Steve