[Mailman-Users] cause of bounces

[Mark Sapiro]

On 10/17/2017 03:38 PM, Lindsay Haisley wrote:
> 
> Any system which REQUIRES DKIM validation to pass is out of compliance
> with RFCs, as I understand it. A DKIM signature which doesn't validate
> MUST be treated the same as no DKIM signature at all.


Actually, it's SHOULD, not MUST in the latest RFC.

And, DMARC doesn't exactly REQUIRE DKIM validation to pass. DMARC treats
a message with no DKIM signature the same as one with an invalid
signature so it is compliant in that sense.


> And I don't believe we're dealing with SPF here, just alignment between
> the domain of an email's author (From) and the IP address of the system
> communicating SMTP server from which the recipient's SMTP server
> received the mail. Correct me if I'm wrong on this, but I don't believe
> a SPF record in DNS is required.


It's not required, but it can enable DMARC to pass IF it passes and the
envelope from domain aligns with the From: domain.

See
<https://mail.python.org/pipermail/mailman-users/2017-October/082621.html>.

-- 
Mark Sapiro <mark at msapiro.net>        The highway is for gamblers,
San Francisco Bay Area, California    better use your sense - B. Dylan