Here are the step to take to setup your Hosted Exchange account on your iPhone.
1. Click on the "Settings" icon on your main iPhone screen.
2. Click on "Accounts & Password".
3. Click on "Exchange".
4. On the next screen, type in your email address & description, click Next.
5. Next window click on "Configure Manually".
6. Type in your email address (example email below) and password and click "Next".
7. Next you'll see the account verifying if you entered in your information correctly.
8. The next window will come up, type in "exchange.infoquest.com" for the server.
9. Next window, leave the "Domain" section blank, type in your full email address & password, click Next.
10. If you typed everything in correctly, you'll see the check marks on the right hand side.
11. You'll see that the "Mail" slide will be on, turn on anything else you'd like to use...i.e. calendars...etc.
Then click "Save"