"The Mailbox you are trying to access isn't currently available" error when you use OWA Premium to try to delete an item that is in a shared mailbox

Symptoms

Consider the following scenario:

• You create a user account that does not have a mailbox in a Microsoft Exchange Server 2010 environment.

• You configure the user account to have full access permissions for a shared mailbox.

• The user logs on to the shared mailbox by using the Premium interface of Microsoft Outlook Web App (OWA Premium).

• The user tries to delete an item that is in the shared mailbox.

In this scenario, the user receives the following error message:

Cause

This issue occurs because OWA Premium requires the user to have a mailbox when OWA Premium tries to create the security context. If the user does not have a mailbox, a UserHasNoMailboxException exception is thrown.

Resolution

To resolve this issue, install the following update rollup:

2529939 Description of Update Rollup 3 for Exchange Server 2010 Service Pack 1

Status

Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.