Moin, as some more notifications started to stack up about bouncing messages from various openbsd mailinglists (and my logs start to reach two digit numbers over the past two weeks), i figured it might be good to send a note about this:
The openbsd mailinglists break (for reasonable reasons) DKIM on messages (see, fore example this thread from 2019 here: https://marc.info/?l=openbsd-misc&m=156612931229416&w=3 ). Also, Mail-From: is not rewritten when sending out messages. Hence, if you are subscribed to an OpenBSD mailinglist, have an SPF policy ending in "-all" and a DMARC policy of "p=reject", your messages will be bounced by all recipients who evaluate and follow DMARC. See: https://doing-stupid-things.as59645.net/email/mailinglists/dmarc/2022/05/19/sending-an-email.html Options are: - Subscribers relax their DMARC settings - Subscribers use a dedicated sender domain if relaxing their main domain is not possible - Mailproviders allowlist the openbsd mailers to skip by DMARC (only possible when you controll your mailserver) With best regards, Tobias
