Samsung Galaxy 3 w/ Verizon, cannot sync email with Exchange Active Sync

Set up the Exchange Active Sync account on a new Samsung Galaxy S3 and it will not sync with my work email account using Exchange 2010. The domain and user information are correct, I have set up the account twice and deleted cache, rebooted phone and nothing works. The Verizon APN is preconfigured and cannot be changed but I think that is part of the problem. I have set up other smart phones on my exchange server with no problem. Our firewall is not the problem, I tested that already. Any suggestions other than using a third party app such as NitroDesk?