Are you restarted saslauthd before imapd? "Socket operation on non-socket" usually means inaccessible saslauthd.pid
Sorry, I am newbie in Cyrus and as a sysadmin in general. My FreeBSD directory /var/run/saslauthd/ contains also three links to saslauthd, saslauthd-rc and sasldb2.db besides of mux, mux.accept, and saslauthd.pid itself.
Vladas Palubinskas
https://az.on.lt/
