You must use the Outlook app to access your Office 365 account on Android. Here's how you can update it:
1. Download Outlook from the Play Store.
2. Open the app, and choose "Get Started"
3. Enter your CU email address.
4. Choose "Work or School" if it asks whether you have a "Work or School account" or a "Personal" account.
5. Enter your password, and approve your sign-in with MFA (if applicable).
6. Hit "Skip" in the bottom right to proceed. "Continue" will ask you to add another mailbox.
7. You will receive a brief ad for Focused Inbox. It is an automatic filter that Outlook uses. Feel free to either skip it, or read through it.
8. You are now on your Inbox page! Please give your phone 15 minutes to sync down your emails, and you will be good to go!