Some applications such as Outlook, Apple Mail, and Microsoft Office will require the use of an app password in place of your account password when you enable multi-factor authentication for your email. To generate an application password follow the steps below:

1. Go to https://portal.office.com/account/#security
2. Enter your email address and password

3. Click Security and Privacy > Additional Security Verification > Create and manage app passwords

4. Click Create and give it a name

5. Record and retain the app password then click close

This code is used in lieu of your regular email password for Outlook. Apple Mail, etc.