From nicolas at schodet.fr  Tue Apr 14 20:56:02 2026
From: nicolas at schodet.fr (Nicolas Schodet)
Date: Tue, 14 Apr 2026 21:56:02 +0200
Subject: [Debian-lego-team] Disabling subject and body modification
Message-ID: <ad6b0spifDu3FyUL@schodet.fr>

Hi all!

I am not sure we talked about it before, I would like to disable subject
and body modifications for the mailing list, mainly because this makes
the DKIM signature fail.

For example, here is a header generated by my server on a message we
received previously on the list:

Authentication-Results: riva6.ni.fr.eu.org;
        dkim=pass header.d=alioth-lists.debian.net header.s=alioth-lists-01 header.b=s2mNAjJU;
        dkim=fail ("body hash did not verify") header.d=outlook.com header.s=selector1 header.b=MNmtrH8A;
        spf=pass (riva6.ni.fr.eu.org: domain of "debian-lego-team-bounces+nico=ni.fr.eu.org at alioth-lists.debian.net" designates 2001:ba8:0:2c77:0:4:0:1 as permitted sender)
        smtp.mailfrom="debian-lego-team-bounces+nico=ni.fr.eu.org at alioth-lists.debian.net";
        arc=reject ("signature check failed: fail, {[1] = sig:microsoft.com:reject}");
        dmarc=fail reason="SPF not aligned (relaxed), DKIM not aligned (relaxed)" header.from=outlook.com (policy=none)

The important part is that DMARC fails, because the message is not SPF
aligned and DKIM signature fails.

SPF alignement failure is expected as this is a mailing list.

DKIM failure is because the mailing list software modifies the body and
the subject of the message.

I took an old message from outlook because it shows a sending server
configured both for DKIM and SPF. However I can show the same problem
when the message is sent by my server.

On lists.debian.org, they do not modify the subject and body.

Do you agree?

Can this be changed in the list admin interface? Do anyone of you have
access to it?

If not, I plan to contact the alioth-lists admin.

Thanks,

Nicolas.