You may access the mail by following the steps below.
To access mail:
Login into control panel.
Click on Mail Manager option present in left frame. List of installed mail domains will be displayed. click the mail domain which you want to administer or for which you want to check the mail.
The web based mail interface will be displayed for the domain. Provide the login information to enter into mail server.
Alternately mail can be accessed directly if you know the port on which mail server is running. e.g. http://www.mydomain.com:8383 . Where 8383 is the port number where mail server's web based interface is running.