Incoming SMTP in the year 2017 and absence of DKIM

William Herrin bill at
Wed Nov 29 17:24:55 UTC 2017

On Wed, Nov 29, 2017 at 12:17 PM, Stephen Frost <sfrost at> wrote:

> * William Herrin (bill at wrote:
> > On Wed, Nov 29, 2017 at 12:03 PM, Eric Kuhnke <eric.kuhnke at>
> wrote:
> > > How much weight do you put on an incoming message, in terms of adding
> > > additional score towards a possible value of spam, for total absence of
> > > DKIM signature?
> >
> > Zero. DKIM for mailing lists is a horribly broken design and legitimate
> > mailing lists are second only to spam in quantity of SMTP transactions.
> Eh, that's really not accurate, imv, and some folks who run mailing
> lists have put in serious effort to make sure to *not* break DKIM
> signatures (which is certainly possible to do).

Alright, so "horribly broken design" overstates the case but there are
enough problems that weighting the absence of DKIM at something other than
zero will surely do more harm than good.

Bill Herrin

William Herrin ................ herrin at  bill at
Dirtside Systems ......... Web: <>

More information about the NANOG mailing list