gordon@dickens.com writes:
the mailman3 service always exits immediately after the command "systemctl start mailman3".
This is normal, The mailman command forks a separate daemon to manage all Mailman processes, then exits.
when I browse to the mailman3 web interface then I get the following error:
Something went wrong Mailman REST API not available. Please start Mailman core.
This is not normal. It could be that Mailman is running but Postorius and Mailman disagree about which port.
What does "systemctl status mailman" say, in full? (As above, it will say Mailman has exited. What's important is if it says there are other errors detected.) What does "journalctl -S HH:MM -u mailman -x" say? HH:MM should be a minute or so before you most recently started mailman with systemctl. What does "ps -e -f -u mailman" say? There should be a dozen or so processes running. Does systemctl stop mailman /opt/mailman3/venv/bin/mailman start work better? The systemd commands are useless, but you can check that the runners are active with the ps command above.
Failing all that, does rebooting help?
Steve