1. Tap Settings.
  2.  Tap Mail,
  3.  Tap Accounts
  4. Tap Add Account (found at the bottom of email accounts
  5. Tap Exchange.
  6. Enter your Email address and Description, Tap Next.  The phone will then verify your settings and ask for the Password.
  7. Enter your Password and Tap Next.
  8. Autodiscover will try to find the settings you need to configure for your account. When successful you will see the Blue Ticks appear.
  9. Choose the options that you want synchronized to the iPhone. 
  10. If autodiscover cannot find your settings, enter the following information:
    FieldWhat to enter
    Serveroutlook.office365.com
    DomainLeave this field blank
    UsernameEnter your full email address (for example, holly@coolexample.com)
  11. Tap Next.
  12. Tap Save.

Return to your home screen and open the Mail app — you should see some email messages, in your new inbox!

To make sure you can send messages, compose an email and send it to yourself.