MS Outlook - Hosted Email On An iPhone

Tap the Settings icon on your phone

In the Settings select the option Mail, Contacts, Calendars 

Select the option to Add Account. 
 

Select the option for Microsoft Exchange. 

Enter the information requested in the Email, and Password boxes. You need to enter your full e-mail address in the Email box. The Description can be set to anything you would like.

Tap Next on the upper-right corner of the screen. Your iPhone will automatically find the settings it needs to set up your account.

Choose the type of information you want to synchronize between your account and your device, and then touch Save. By default, Mail, Contacts, and Calendar information are synchronized.