Out of office is not working in Outlook.

I have a brand new installation of Exchange 2013 Standard Server. Everything works properly with the Out of Office Reply in Outlook clients (It works when client connects through OWA). Every time user trying to access this feature, it gives them the following error message, "You Out of Office setting cannot be displayed, because server is currently unavailable. Try again later."

I already did "Test E-mail AutoConfiguration" and its completed without any errors. I also checked OOF URL and it completed without any errors.

Any other ideas what might be going on?

Thank you in advance for the reply.

Serge