If you need to change the name of roundcube to your org ..
You can add your org name in the following lines under roundcubemailXXX/config/main.inc.php file :
// add this user-agent to message headers when sending
--> $rcmail_config['useragent'] = 'Roundcube Webmail/'.RCMAIL_VERSION;
// use this name to compose page titles
--> $rcmail_config['product_name'] = 'Roundcube Webmail';