[dmarc-discuss] Rejecting multiple From: mailboxes (was Re: Several remarks)

[David F. Skoll]

On Tue, 31 Jan 2012 16:42:19 +0000
Franck Martin <fmartin at linkedin.com> wrote:

> Agree, but if you are a sender and using DMARC, you will ensure that
> these requirements are met because you know the receiver at the other
> end will generate a DMARC fail and apply your p= policy.

That's no good.  The spec says messages with multiple addresses in From:
SHOULD be rejected.  It doesn't say anything about whether or not any
of the domains in the From: header should be checked to see whether or
not they're using DMARC.  And in fact a reply from Michael Adkins strongly
implied that one SHOULD NOT attempt to do DNS lookups on the From:
addresses to see whether or not they are using DMARC.

This part of the spec needs to be changed.

Regards,

David.