Created attachment 139658 [details]
Mail in question
I got the attached sample over lists.freedesktop.org . As you can see in the Authentication-Results header for the libreoffice.org domain, the dkim validation performed by opendkim failed.
Moreover calling with python3/dkimpy 0.8.8
also emits False.
Why don't the signature validate? Was the mail changed on its way?
Why does DKIM-Signature h=.. contain twice from:date: and which software do you use for signing?
Mailman transforms the mail in ways which break the DKIM signature. We are supposed to be stripping the signature to account for this, but it looks like a change in Mailman upstream meant this didn't always happen.
I've changed the configuration to strip more aggressively now; hopefully that takes care of it. Thanks for the report.