Some applications do not support modern authentication. The most common is Gmail (the default mail application for the majority of Android phones). Below you will find instructions on creating an App Password, which is a single use password locked to a particular App or program.
Navigate to office.com.
Select your name in the upper right corner of the screen, then select My Account:
On Your Account screen, open Security and Privacy:
On your Security & Privacy page, select Additional security verification:
This will expand this selection, you can now follow the link to 'Create and manage app passwords':
On the next page, you will select +Add method, and the App Password:
Give the new app password a description:
The next screen will show your newly created app password. Use it on the application NOW, as the screen states, it will not be shown again. After you enter the app password and confirm it works, you can return to the screen and select Done:
Should the password no longer be needed (it was used for an email program on your phone, and you have purchased a new phone, the next screen will allow you to delete this password:
You have now created an App Password for your needed App.