For your information, When you are running Exchange server 2010 active sync on a mobile device, make sure that the user you are testing is not a member of any administrator group. In Exchnage 2010, by default if a user is a member of any Administrator group, then he will not be able to sync his mobile device..
Make sure that you have to open TCP Port 443 on the firewall to listen.
If you have to test a user, who is falling under any administrative group, then on active directory users and computers –>view menu select Advanced options–>then user properties->select the security tab->click advanced and ensure that inheritable permissions check box has to be checked