systemd 249 (used in Ubuntu 22.04 LTS) throws the following error:
/etc/systemd/system/stalwart-mail.service:16: Standard output type
syslog is obsolete, automatically updating to journal. Please update
your unit file, and consider removing the setting altogether.
/etc/systemd/system/stalwart-mail.service:17: Standard output type
syslog is obsolete, automatically updating to journal. Please update
your unit file, and consider removing the setting altogether.
This is caused by StandardOutput=syslog and StandardError=syslog found
in install.sh, which are as the error suggests obsolete options that
should not be used.[1] They have "correct" settings in
stalwart-mail.service, but these settings are also the implicit
default, which means they are not necessary.[1]
This was patched in systemd #15812 in May, 2020.[2]
I have tested this by simply removing the values in
/etc/systemd/system/stalwart-mail.service on my server, running
'daemon-reload' and restarting the service, then confirming that logs
are still being written to journalctl as well as /opt/stalwart-mail/logs
[1]: <https://github.com/systemd/systemd/issues/15807#issuecomment-628528787>
[2]: <https://github.com/systemd/systemd/pull/15812>
systemd deprecated `syslog` output and automatically converts it to `journal`. Making the change in the unit file will silence the warning notice on service (re)start.