Bron helped me track it down. Starting in Cyrus v2.4.13, there is a check
to see if we're running on a standard Murder backend. If so, some code to
update the mailbox list is skipped.
The code was identifying a server as a backend server by checking for the
presence of the "proxyservers" conf
I recently upgraded our Cyrus murder cluster from v2.4.12 to v2.4.16.
Since then, I have come across an interesting race condition. When
connected to a frontend server, if I create a mailbox and then immediately
try to select it, I will get an error message.
Frontend IMAP telemetry:
<13474919
