Re: Microsoft O365 labels nanog potential fraud?

[William Herrin <bill () herrin us>]

On Wed, Mar 29, 2017 at 12:24 PM, Alan Hodgson <ahodgson () lists simkin ca>
wrote:

> 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 () nanog org. Checking against the message header
> "from"
> > 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
> to
> test that parts of the message haven't been altered. DMARC adds policy to
> both
> to check them against the header From:. Mailing list software may not work
> with DMARC-reject senders (but Nanog does).

Hi Alan,

I accept your explanation as the correct one.

Regards,
Bill Herrin

-- 
William Herrin ................ herrin () dirtside com  bill () herrin us
Dirtside Systems ......... Web: <http://www.dirtside.com/>