Date: 2024aug12 Product: Roundcube webmail OS: Linux Q. Roundcube: how to setup a local IMAP server A. My IMAP server expected a STARTTLS connection so I prefixed the hostname with tls:// Then the handshake was failing with a host name of localhost so I changed it to %n which is the fully qualified hostnmae and that worked. In file /etc/roundcubemail/config.inc.php

$config['default_host'] = 'tls://%n';