I have setup Exchange Server 2013 as a fresh install and imported the mailbox from our old Exchange Server 2007 installation. Everyone with access to Outlook can see their mailbox, send/receive email etc. However mobile access does not work.
The external domain is pointing at the external IP, and traffic on port 443 is being forwarded to the new Exchange server. When I attempt to add my account to my iPhone using the external domain, it tells me the certificate has been issued for the internal server name and it cannot continue.