Go to Accounts and add XMPP
Enter the name you want for the dukgo.com email
then enter dukgo.com for domain
enter a password
do not check remember password now
Do check create account.
After you click "add" a screen will present that will verify completion and you will be able to then check "remember password".
You will now be able to log on to dukgo.com if you wish to enter a forwarding email.
At times it takes a few tries to get the account to activate for some reason.