Add Email to Your Phone using the Outlook App

On an Iphone:

1. Tap Settings.
2. Tap Mail, Contacts, Calendars.
3. Tap Add Account.
4. Tap Exchange.
5. Enter your Office 365 email address and password and tap Next.
6. Wait for it to show verified.
7. Select the services you want to sync to your iPhone or iPad.
8. Open the mail app on your phone to view your new mail account.

For an Android: 

1. Open your device’s Settings app. Tap Accounts. If you can’t see ‘Accounts‘, tap Users & accounts.
2. At the bottom, tap Add account.
3. Tap Exchange.
4. Enter your Microsoft® Office 365 or Exchange ActiveSync email and credentials.