I have an Exchange 2013 installation that appears to work correctly and Outlook Anywhere correctly connects to Outlook running on a remote workstation. However, when I try to connect an Ipad or Iphone the IOS device correctly connects and verifies the connection using the mail setup however when you open the mail account in IOS mail it appears to connect but displays No Mail. If you then refresh the display, forcing the IOS device to attempt to sync it sometimes reports it cannot connect or simply does nothing. I have only ports 80 and 443 open in the firewall and I dont think any others are required since the outlooks work on the laptops. If you attempt to send a message a local outbox is created but the mail is not sent but reports 'Cannot send Mail The message was rejected by the server'
The main external DNS for the site is remote from the server however I have created a copy of it on the local DNS pointing to the internal addresses, I cant see that is significant.
IOS reports its last update of the mailbox was when it created on the IOS device, I have checked that the device is not listed in the banned devices in Exchange 2013. The only other things I can think of that may be significant is that the Exchange Server is running as a VM on a hyper V host and the Domain Controller has the Essentials role installed and is linked to Exchange.
I am sure I am missing something obvious?