The following article will take you through the process of setting up your Hosted Exchange email address on your IOS Tablet / Phone.
Step 1) Go to Settings > Accounts & Passwords > Add Account
Step 2) Select Exchange from the list of account types
Step 3) Enter your email address and a description for the account. When prompted to click on 'Sign In' and not 'Configure Manually'
Step 4) After selecting Sign In enter your password for your email address and then click Sign In. When promoted on the next screen select 'Accept'
Step 5) Select the information that you would like to sync to your device and then click Save. Your email address has now been added to your device!