Setup Hosted Exchange on your iPhone
Start by opening the ‘Settings’ app on your iPhone.
Scroll down and select ‘Accounts & Passwords’.
Tap on ‘Add Account’ and select ‘Exchange’.
Enter your full email address and a description for the account. Click ‘Next’.
Enter your account password and click ‘Next’.
Choose what you want to sync with the server (Mail, Contacts, Calendars) and click ‘Done
Your iPhone will now try to verify your Exchange account settings. Once it is successful, your Exchange account will be setup and ready to use. You can open up the default Mail app on your iPhone to access your Exchange mailbox.