Symptoms
After you upgrade to Microsoft Exchange Server 2013 Cumulative Update 6, you cannot see online archive mailbox in Microsoft Outlook.
Cause
This issue occurs because autodiscover is returning the primary mailbox settings for the online archive mailbox.
Resolution
To resolve this issue, install Cumulative Update 7 for Exchange Server 2013.
Status
Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.