You can use either the webmail interface or an email client. If you need help configuring email clients, please visit the step-by-step guides for configuring MS outlook and Mozilla Thunderbird.
You can easily access your WebMail interface by just visiting: http://www.yourdomainname.com/webmail,
where yourdomainname.com is your actual domain name.
Please use the full e-mail account's username to login to the webmail interface or when setting your e-mail client software. Example: user@yourdomainname.com instead of user. Once you login, you can choose between three webmail clients: Horde, RoundCube and SquirrelMail. It is up to you to decide which one you like better.