to your e-mail address (firstname.lastname@example.org): Do not include the word "mail"
Previous Method to enter username and domain!
CORRECT METHOD TO ENTER USERNAME!!!
If Outlooks saves your password:
Under Outlook’s Tools menu select Accounts and change your user name from etsu\username to email@example.com as shown:
Outlook will ask permission to autodetect your new account settings, click “Allow”. It will probably do this several times:
Lastly, check the box "Always use my response for this server" - Allow.