continuously asks for username & pw even though already in place
 

In setting up outlook when I get to test account a box appears asking for
username & Password which is already filled in with correct info. When ok is
clicked it goes away and seconds later comes back. After clicking OK numerous
times got it to take then long wait process for test email, then again the
box appears, but this time with the outgoing server box asking for same user
name and PW info, which is in place, but clicking OK will not take. Please
help, why is it doing this? and how do I make it stop?