Fetching tickets with incoming emails

I have tired to set the system up for fetching. THe out going email works with using helpdesk and the email. But when I trying for the incoming, I put the helpdesk email in and the user and ow for email exchange. But it grab everything but the emails going to helpdesk@

And also when I try a different login and pw I get the error: FAILURE :Email Settings saved successfully. But error occured while trying to check connection with mail server - Authentication Failed using the given username and password.

and the fetching does work.

Does the email box have to have admin rights on the exchange or can we use a dl box?