Outlook on Mac Says "Bad Username or Password"

There are two Macs in an area of our library equipped with Microsoft Outlook. One of them currently gives a "Bad Username or Password" area when an attempt to check the user's email is made; Outlook is working properly on the other. I checked to ensure the Outlook settings were the same on both machines.

The user with the troubled Mac remotes in to a Windows 7 desktop that also has Outlook with an email account set up for her. On it, things worked fine; she's also able to log into webmail without error. That tells me something is borked with her email setup.

I tried deleting & recreating her email account on her Mac; that failed to fix the issue, though.

Any input would be appreciated.