Activesync error The Connection to the Server Failed
You get the 'The Connection to the Server Failed' error when you try to configure your iPhone for Exchange.
This can be due to permissions issue on Active Directory.
To resolve this issue, open Active Directory Users and Computers
Click on the View menu and select Advanced Features
Open the account properties of that particular user account and go to the Security tab
Click on the Advanced button
Enable 'Include inheritable permissions from this object's parent'
You should now be able to send and receive emails using your iPhone.