Microsoft O365 labels nanog potential fraud?
bill at herrin.us
Wed Mar 29 19:52:15 UTC 2017
On Wed, Mar 29, 2017 at 12:24 PM, Alan Hodgson <ahodgson at lists.simkin.ca>
> On Wednesday 29 March 2017 11:12:33 William Herrin wrote:
> > Both SPF and DKIM are meant to be checked against the domain in the
> > envelope sender (SMTP protocol-level return address) which the NANOG list
> > sets to nanog-bounces at nanog.org. Checking against the message header
> > address is an incorrect implementation which will break essentially all
> > mailing lists.
> This is incomplete.
> TL;DR: SPF checks the envelope sender. DKIM doesn't check anything except
> test that parts of the message haven't been altered. DMARC adds policy to
> to check them against the header From:. Mailing list software may not work
> with DMARC-reject senders (but Nanog does).
I accept your explanation as the correct one.
William Herrin ................ herrin at dirtside.com bill at herrin.us
Dirtside Systems ......... Web: <http://www.dirtside.com/>
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