Roundcube email on the webmail or mail subdomain rather than the URL.

I can access Roundcube email from the clients "client-domain.com/webmail" URL but I don't want that and it doesn't look professional.  I want the mail.client-domain.com or webmail.client-domain.com to work for my clients.  Has anyone got this to work properly?  Also, has anyone been able to connect a gmail account to a Roundcube mail account hosted under CWP?

Thanks,
Andrew