Everything related to your website and email accounts is managed using the online Control Panel, commonly referred to as CPanel.
From CPanel you can:
To access CPanel: mail.remotelyyours.com/cpanel
Username: [user]
Password: [pass]
SImply go to mail.remotelyyours.com/webmail (or your www.yourcompany.com/webmail).
From Webmail, you can see any messages that have not yet been pulled down to your PC, as well as set your Out of Office reply.
You can post your website using FTP (File Transfer Protocol) and go to your website address (IE. www.yourcompany.com), and log in using the same username and password as your CPanel account.
FileZilla is a great free FTP program you can use to post files to your FTP site.