the problem still not fixed
Jul 10 09:13:30 small systemd[1]: Unit opendkim.service entered failed state.
Jul 10 09:13:30 small systemd[1]: opendkim.service failed.
Jul 10 09:13:43 small systemd[1]: Failed to reset devices.list on /system.slice/opendkim.service: Operation not permitted
Jul 10 09:13:43 small systemd[1]: Starting DomainKeys Identified Mail (DKIM) Milter...
-- Subject: Unit opendkim.service has begun start-up
-- Defined-By: systemd
-- Support:
http://lists.freedesktop.org/mailman/listinfo/systemd-devel--
-- Unit opendkim.service has begun starting up.
Jul 10 09:13:43 small opendkim[7822]: /etc/opendkim/keys/default.private: open(): No such file or directory
Jul 10 09:13:43 small opendkim[7822]: opendkim: /etc/opendkim.conf: /etc/opendkim/keys/default.private: open(): No such file or directory
Jul 10 09:13:43 small systemd[1]: opendkim.service: control process exited, code=exited status=78
Jul 10 09:13:43 small systemd[1]: Failed to start DomainKeys Identified Mail (DKIM) Milter.
-- Subject: Unit opendkim.service has failed
-- Defined-By: systemd
-- Support:
http://lists.freedesktop.org/mailman/listinfo/systemd-devel--
-- Unit opendkim.service has failed.
--
-- The result is failed.
Jul 10 09:13:43 small systemd[1]: Unit opendkim.service entered failed state.
Jul 10 09:13:43 small systemd[1]: opendkim.service failed.