I just going to take you through how to set up office 365 on your iPhone ISO devices, make sure you have your Microsoft login and password to hand.
Before we begin you need to download load Microsoft Authenticator App from the Apple Store, use your email address and password to sign in to your Microsoft Authenticator App.
Keep this app on your phone as from time to time you may be prompted to confirm your account, also if you sign in on other devices you be asked to confirm this is you signing in.
Let Get Started
Go to Setting and Click on Mail and then click on Accounts, now click on Add Account.
Now Click on Microsoft Exchange
Email: Your email address goes here
Description: Enter your Name here
Now on the pop-up window click on Sign In
Next screen is the Microsoft Sign in Screen, type in your password and click Sign In.
You may be asked to open up Microsoft Authenticator App to confirm
Now your email is set up and ready to use.