For personal Android devices, you are required to install the Intune Company Portal app on your device as well as the Outlook for Android app.
Open the Google Play Store. Search for and download the Intune Company Portal app.
If you haven't already, install the Outlook for Android app from the Google Play Store.
Open the Outlook for Android app.
Tap Get Started.

Enter your company email address, then tap Continue.

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If prompted, enter your email account password, then tap Sign In.
Notes:
Your experience may vary depending on your company’s requirements. For example, you may be prompted to authenticate by using the Microsoft Authenticator app or verify yourself by text or phone. For details, see Security Info Overview.
Your company may have also implemented controls that will require you to Register before you can proceed. By registering, you are verifying your identity so the device can be validated by your organization. If prompted to register your device, tap Register.
If prompted to add another account, tap Maybe Later.
Tap Skip or swipe through the feature screens.
The message, Your organization is now protecting its data in this app. You need to restart the app to continue, appears. Tap OK.
Restart Outlook for Android and set up a Personal Identification Number (PIN) when prompted.
You're now ready to start using Outlook for Android!
Get the most out of Outlook:
Optimize the Outlook mobile app for your phone or tablet
Outlook for Android Cheat Sheet