When you enable Multi-Factor Authentication (MFA) in Office 365, you will need to update the passwords of your existing email accounts on your iOS devices (iPhone/iPad).   You may get a prompt like the one shown below shortly after completing MFA setup.  Click “Edit Settings” and skip to step 3 below.

Update Email Password Alert

If you do not get this alert, you will need to update the email account using the steps below.

1. On your mobile device, go to Settings > Passwords & Accounts

Passwords and Accounts

2. Select your email account to update

Select Mail Account

3. Select Re-enter Password

Re-Enter Password

4. Enter your email password (this is your email password and not the app password) and click Sign In.

Enter Email Credentials
5. After you enter your email password it will send a code to your mobile device via SMS. Enter the code and click Verify.

Enter MFA Verification Code