This configuration will not synchronize your calendar or contacts. If you have a Full Exchange account you may want to consider the knowledge base article on configuring Full Exchange on iPhone.
Your email address is your username and you can put anything you wish in the Description.
Select IMAP as the account type. You'll need to enter the incoming and outgoing server information on this screen. Use the below screenshots as reference.
Incoming server host name is imap.exg6.exghost.com
Outgoing server host name is smtp.exg6.exghost.com and you must fill in the username and password again.
Click Save and you're done!