Re: [dmarc-ietf] Sender vs From Addresses

Hector Santos <> Thu, 25 March 2021 22:26 UTC

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Date: Thu, 25 Mar 2021 18:26:07 -0400
From: Hector Santos <>
Organization: Santronics Software, Inc.
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Subject: Re: [dmarc-ietf] Sender vs From Addresses
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On 3/25/2021 2:23 PM, John R Levine wrote:
> While I am not opposed to a future tweak to DMARC to add some way to 
> say
> that A can sign for B, even if we did it, it would be a long time if 
> ever
> that DMARC verifiers implement it.  RFC 6541 added a third-party 
> signature
> option to DKIM in 2012, and after nine years, nobody implements it. 

Wildcat! SMTP implements RFC6541 "Authorized Third Party Signature" 
(ATPS)/ I'm sure I am not the only one and/or others have the options 
to enable it.

There are wizard for ADSP+ATPS and DMARC+ATPS:

It works in proving the assertion by a 1st party Author Domain 
authorization for the existence of a specific 3rd party signer domain 
signature. Results are stamped in "Authorization-Results" header.

Add "atps=1" to your DMARC record and create a ATPS record to 
authorize 3rd party signature domains.

These domains are authorized to resign mail for the domain

jchjykxmwknbyfge2bg4td6add264olh._atps TXT   ( "v=atps01;;" )
kjshf2duqstols65zbhuytbbyr3zdecf._atps TXT   ( "v=atps01;;" )
lykm653kj7yxeia665va7lszzthcx7jj._atps TXT   ( "v=atps01;;" )
pq6xadozsi47rluiq5yohg2hy3mvjyoo._atps TXT   ( "v=atps01;;" )
tudfisabn5dz3vjm2kxcehc5attdbqh6._atps TXT   ( "v=atps01;;" )

It can be managed like any other system.

This allows receivers to support a MAILING LIST that has resigned mail 
- the key problem we had since ADSP and now since DMARC because DMARC 
never bothered to even address the main concern with ADSP - the lack 
of a method to authorized a 3rd party.

ATPS offers it.

As to why the IETF.ORG mailing list does not support it or explore it 
and has chosen instead to rewrite, I don't know, but its so simple --- 
a DNS Lookup without any 5322.From tampering.

Hector Santos,