In order to add a new user you need to specify the username, password, home directory, and whether pop email and ftp access is allowed.
POP simply allows the user name to check email.
You will however need to define the email address after creating the username, need to define the email account. You can do this by selecting Create Email Accounts from your main WAMT page. When you create an FTP account the WAMT will create a directory under your root directory with the same name as the username. When this username FTPs into the site they will only have permission to enter their personal space.