I've ran through the tests at http://testexchangeconnectivity.com/ and The ActiveSync test is passing, but with warnings.
This is the warning I get:
Only able to build certificate chain when using the Root Certificate Update functionality from Windows Update. Your server may not be properly configured to send down the required intermediate certificates to complete the chain. Consult the certificate installation instructions or FAQ's from your Certificate Authority for more information.
I purchased the SSL cert from godaddy, but I'm not quite sure where to go from here.