I feel like I'm chasing my tail on this one. I've done several installs of roundcube on Linux machines and currently have this issue on one of them, but on that one all I have to do is create a "mail" folder in the /home/<username> that is owned by the user.
On Mac OS X 10.8, I'm not sure what is going on.
A bit of history of this machine. Brand new Mac Mini running 10.8.4 Server. I used TimeMachine to restore the setting from the clients previous MacMini that died, also running 10.8.4 server. Ran into an issue with none of the services coming up so I reinstalled the "server" part of it and repaired permissions.
I did what I normally do when setting up roundcube on a linux machine and get as far as bringing up the login screen and connected to the database properly, but when any user tries to log in, they get "Connection to the storage server failed"
I'm guessing this is because the webserver doesn't have write access to a particular directory??? Really don't know where to look. The roundcube error log has this line:
[30-Jul-2013 15:19:12 -0800]: IMAP Error: Login failed for rose from 192.168.1.88. Could not connect to ssl://bogus.com:993: Connection refused in /opt/webapps/webmail/program/lib/Roundcube/rcube_imap.php on line 184 (POST /webmail/?_task=login&_action=login)
(username and server changed to protect the innocent)