2FA and Outlook
A friend’s company turned on 2fa for their office 365. When people logged into office.com they were prompted to 2-factor authenticate with the system. Some choose to call in, some choose text, and others choose the app. It was doing good, but outlook gave them troubles. It turns out that office 2013 and office 2016 installs struggle with 2fa. However, there is salvation! A registry edit.
for office 2013:
for Office 2016
Set this to a REG_DWORD of 1.
For more information, you can read all about it from the Microsoft documentation page: