There was the same error in another thread: Nethserver 8 Not accepting any email - #15 by derilium
Let’s check if the port is open:
[root@ns8rockytest ~]# ss -tlp | grep 11332
LISTEN 0 4096 127.0.0.1:11332 0.0.0.0:* users:(("rspamd",pid=10741,fd=67),("rspamd",pid=9502,fd=67))
You could try to restart the rspamd service/container:
runagent -m mail1 systemctl --user restart rspamd