You enable the MAPI over HTTP transport protocol in an environment that has Microsoft Exchange Server Cumulative Update 5 installed.
You have two users (user A and user B) in the environment. Both of their mailboxes have on-premises archive enabled.
You grant the Full Access permissions on user B to user A.
You log on to the mailbox of user A through Microsoft Outlook 2013 Service Pack 1.
In this scenario, you can see the primary mailbox of user B in the Outlook profile. However, his or her archive mailbox is not displayed there.
To resolve this issue, install the following cumulative update:
2961810 Cumulative Update 6 for Exchange Server 2013
This issue occurs because the Autodiscover service returns an incorrect SMTP address of the archive mailbox of the delegated user when the Autodiscover request is sent from a MAPI over HTTP Outlook profile.
Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.
For more information about how to enable the MAPI over HTTP protocol, go to the following Microsoft website: