You can try to regenerate the DKIM configuration with sudo yunohost tools regen-conf opendkim.
Found in a related post (in french) : Signer les mails d'un domaine secondaire avec dkim
You can try to regenerate the DKIM configuration with sudo yunohost tools regen-conf opendkim.
Found in a related post (in french) : Signer les mails d'un domaine secondaire avec dkim