[RCU] Timeout on login

FreeBSD 11.1, roundcube 1.3.3, php70. When I try to login to any account I get:

[27-Dec-2017 06:41:47 -0700]: <c7cd1119> IMAP Error: Login failed for user@example.com against mail.covisp.net from xx.xx.xx.xx. Empty startup greeting (mail.covisp.net:993) in)

in errors.log

I changed

$config['default_host'] = 'tls://mail.covisp.net/';

to

$config['default_host'] = 'imaps://mail.covisp.net/';

and now get

"Could not connect to ssl://mail.covisp.net:993"

Do I *have* to use localhost if the mail server is the same machine? I wanted the configuration to be the same across multiple machines, so I was using the FQDN instead.