
Roundcube webmail is a browser-based multilingual IMAP client with an application-like user interface. It provides full functionality you expect from an email client, including MIME support, address book, folder manipulation, message searching and spell checking.
In this tutorial we will show you how to install Roundcube on your Webmin so every user on the server could access its email through it.
This tutorial was prepared with our "CentOS 6 Webmin" template and is meant to work on our self-managed virtual private servers.
0. Preliminary requirements:
"CentOS 6 Webmin" template installed on server;
Fully updates server software (yum update or through Webmin control panel).
1. Connect to your Webmin
To access your Webmin control panel go to http://your-hostname:10000 or http://your-server-IP:10000 and login in with your admin account.

2. Selecting Virtual server
Select Virtualmin control panel. Either create a new virtual server (e.g. roundcube.hostname) or use an existing one and select menu "Install Scripts".
3. Selecting install script
In scripts list select Roundcube and press "Show Install Options" button.

4. Confirming your setup options
If you have created special virtual server for webmail client like in this tutorial (http://roundcube.hostname) then you should select "At top level" in "Install sub-directory under" line. Otherwise you should select other option which will install Roundcube to http://your-virtual-server/roundcube/.

5. Confirming "At top level" setup
If you are installing Roundcube "At top level" you will be asked to confirm setup because it will delete everything in your virtual server "public_html" folder.

6. Accessing your Roundcube
After setup is complete depending on your install options you will be able to access your Roundcube webmail client either through http://roundcube.hostname or http://your-virtual-server/roundcube/

Every user in your server will be able to use this webmail client. They just have to use their full email address as username.