Exchange 2013 Cannot connect outlook client

[clareq]

We've built a new Exchange 2013 Server. All users are on, OWA and Activsync both work without any Certificate errors. However, I am unable to connect an Outlook 2013 client to Exchange.

I get the message

"Outlook cannot log on. Verify you are connected to the network and are using the proper server and mailbox name. The connection to Microsoft Exchange is unavailable. Outlook must be online or connected to complete this action."

 

OK-ing that then gives the error:

The name cannot be resolved. The action cannot be completed

which strikes me as strange, as the name is auto populated, I assume by autodiscover.

 

I'm running out of things to try - HELP!!

[sukh]

Same issue externally or only on LAN?

[clareq]

Sorry fixed - enabled Outlook anywhere, and configured Outlook to connect by http.