Exchange 2013 OOF not working for migrated accounts

We are having a problem with the Out of Office responses in Exchange 2013. 
We are getting the error “Your automatic reply settings cannot be displayed because the server is currently unavailable. 
Try again later.”  I have been through several help articles that I found on the internet and so far none have resolved the problem. 
Autodiscover is working as expected when connecting an Outlook client – and I can access the url identified by the “Test Email AutoConfiguration” tool for OOF – it returns the xml document as expected. New accounts created in this domain work, but the
problem occurs accounts that were migrated from Server 2003 domain running Exchange 2007. I can also access the OOF settings for a migrated account using OWA. The new domain is 2012 and Exchange 2013 and accounts are being migrated using ADMT through a trust,
which is working as expected.  Only the accounts have been migrated (not mailboxes) and I am not planning to connect the old exchange to the new to do mailbox moves – instead I am just planning to export psts from the old Exchange 2007 server
and then import them to the 2013 server.  The client dns settings are correct and all other connectivity seems fine. 
Any ideas are greatly appreciated.  I have also tried creating a new Outlook profile, turning off Cached Mode, and creating an entirely new Windows profile and Outlook profile. 
I have also tried using Outlook 2007, Outlook 2010 and Outlook 2013. 


I solved this - EWS was disabled for the mailbox.  Set-CASMailbox -Identity User -EWSEnabled $true fixed the problem.