No separate DKIM certificates are necessary for each domain; one cert
for your MX is sufficient.
For example, my MX sala.online.lt (selector sala2022) serves mail for
both @online.lt and @on.lt addresses:
https://emailstuff.org/dkim/check/sala.online.lt/sala2022
https://emailstuff.org/dkim/check/online.lt/sala2022
https://emailstuff.org/dkim/check/on.lt/sala2022
--
Vladas aka Uolys
https://vladas.palubinskas.lt/
2025-12-05 12:23 (+02:00) <[email protected]>:
Hello,
I would like to run OpenSMTPD for two domains, each of which can send
and receive messages.
Right now, I have it set up for one domain, and use a configuration
similar to https://openports.pl/path/mail/opensmtpd-filters/dkimsign
for DKIM.
From my understanding of the DMARC standard, the DKIM signing domain
should match the domain using in From addresses.
I see how to extend this configuration to sign for all domains at once,
but how would I sign with only the domain that was used in the From
address?
