OK, our ActiveSync / Client Access has been working flawlessly for quite a while. Recently we had a user who had a mailbox and user ID move to another AD site and Exchange 2010 server. Once the account was moved back to our site and mailbox to our server we cannot get activesync to work.
Looking into this more and more we finally saw that the redirect URL is for the old CAS server and not the one in our site. Is the a quick easy way to just use ADSI edit or something to change this users redirect URL to the proper one? Appears AD just did not update this correctly when the mailbox / user move back to our AD site was done.