[dev] Improved Deliverability

From: dev=frign.de <Laslo>
Date: Fri, 18 Sep 2026 23:22:01 +0200

Dear fellow hackers,

in the last 1-2 years, many people in the community increasingly had
issues receiving some e-mails from some people on the mailing lists.
This was because DMARC (and associated DKIM and SPF) have become, more
or less, requirements to still inbox at the large mail providers, in my
opinion for good reason. This is why many people adopted strict DMARC
policies.

The suckless mailing lists would break DKIM signatures by modifying
headers. However, without modifying headers mailing lists are just a
bit clunky unless you can really fine-tune your e-mail program, and one
is still relying on DKIM, whereas many only set up SPF to satisfy
DMARC, as DKIM is much more invovled to set up than SPF. However, if
only SPF is set up, all e-mails simply 'forwarded' by the suckless MX
are marked as spam or even outright rejected hard on the server level
(not even let through into spam).

Over the years, technologies like ARC had been proposed, but in the
meantime they were pulled back. The current gold standard is to simply
send out e-mails under the mailing list's host with name-munging.
Currently the header 'Author:' is proposed to preserve the original
author.

In the last few days I worked on setting up strong DMARC, DKIM and SPF
(and also MTA-STS and TLS-RPT) for suckless.org's MX and reconfiguring
mlmmj to follow this gold standard (and also setting the Author field).
Mails will originate directly from suckless, and initial tests are very
positive, as they are cleanly signed.

I am very hopeful that this should finally fix those deliverability
issues. As an added bonus, if someone sends a mail to a list without
specifying it in 'To' or 'CC', one can always identify a mail's origin
now via the 'From' header.

Please respond if you notice any issues.

With best regards

Laslo
Received on Fri Sep 18 2026 - 23:22:01 CEST