How to stop this:
User-Agent: Roundcube Webmail/1.1.4
From appearing in the message headers ?
I'm using dovecot/exim setup with roundcube.
Modify 'useragent' option in config.
Can't find the useragent var in the config file. Which config are you talking about ?
If you can't find it then add it. See defaults.inc.php for an example.