By default members of an AD protected group like domain admins or enterprise admin cannot use microsoft activesync with a exchange 2010 server. They get a error like this: “Result: ActiveSync encountered a problem on the server. Support code: 0×85010014″.
Solution 1: Remove the protected group memberships for this account, more information about protected groups can be found here.
Solution 2: Goto active directory users and computers, turn on advanced features on the view menu. Go to the user account, security tab and tick the advanced button. After that you have to enable Include inheritable permissions from this object’s parent. Now activesync will work.