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Re: [dmarc-ietf] Proposing an extension to DMARC to optionally require SPF and DKIM

"John Levine" <johnl@taugh.com> Tue, 02 April 2013 00:57 UTC

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Date: Tue, 02 Apr 2013 00:57:12 -0000
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From: John Levine <johnl@taugh.com>
To: dmarc@ietf.org
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Cc: jgomez@seryrich.com
Subject: Re: [dmarc-ietf] Proposing an extension to DMARC to optionally require SPF and DKIM
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> Hmm, are you missing the part where several independent clients send
> to the Internet through the same cloud-based email gateway, and
> therefore "-all" in SPF still allows for spoofing if any of those
> clients is trojanized, and DMARC in its current form does nothing to
> solve this problem?

DMARC works fine if the senders behind the cloud each have different
DKIM signatures, which I gather is what Terry was describing, and the
SPF correctly describes the outgoing mail policy.

If you believe that DKIM signatures do not adequately identify a mail
stream, I'd appreciate it if you could explain in detail why not.

R's,
John

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