So your IPhone is not getting Exchange email after setting up your account and it verifying the account during the setup?
Here is what may be going on.
The ‘Cannot Get Mail. The connection to the server failed’ error may be the cause of a simple mis-configuration in the Microsoft Active Directory services for that user. To see if it is this issue you will need to open the Active Directory Users and Computers, Select the VIEW menu from the top and click on “Advanced Features”. Now open the properties on the user having the issue and select the “Security” tab. Under this tab will be windows with user accounts listed and a “Advanced button” at the bottom. Select this button and find the check box “Include Inheritable permissions from this object’s parent” . If this is the problem you will find the box “unchecked”. Just check the box and try again. You should see mail start to flow.