This guide will walk you through changing email settings.
First goto the address bar and put in "http://" then add your domain name (for example if your domain is www.example.com you would add that) then ":81/mailuser/" . For example if your website is "www.example.com", you would put "http://www.example.com:81/mailuser/" in the address bar of your internet browser.

On the next page you will be asked for a username and password in a little box on the logon screen. You will use your FTP username and FTP password in the apropriate boxes.