Cannot send nor receive email via Outlook

Every time I try to access Outlook I receive an error message regarding my smtp. comcast.net

It wants my user name and password which has not changed. After doing many work arounds I am back to the same message. I just don't get it. I cleared my cache etc. As Xfinity really doesn't exist and it is a figment of our imaginations (believe me my phone doesn't work either and no one is home at Xfinity) I need help. I am so IT-dependent and with working at home, I have no work-study IT students to help!