On April 21st users started experiencing excessive login/password requests from Outlook. Central IT, who manages the Exchange email servers, is aware of this problem. There is no ETA as to when this issue will be resolved.
Possible solutions to get you by for the time being:
1. Cancel the login request. Sometime this is all that is needed.
2. Enter "IASTATE\netid" in the username box (insert YOUR netid not the word "netid", example IASTATE\smith) and your password in the password box.
3. Enter your full email address in the username (example: firstname.lastname@example.org) box and your password in the password box.