You grant User A the Full Access permission to User B’s mailbox in a Microsoft Exchange Server 2010 environment.
User B creates some meetings or some appointments.
User A tries to view the free/busy information of User B.
In this scenario, User A can only see the time of the meetings or the appointments. However, User A cannot see the detailed free/busy information, such as the subject or the location of meetings or appointments.
This issue occurs because the Exchange server checks the permissions for the mailbox incorrectly.
To resolve this issue, install the following update rollup:
2706690 Description of Update Rollup 4 for Exchange Server 2010 Service Pack 2
To work around this issue, grant User A the folder-level permission for the Calendar folder of User B’s mailbox.
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 manage Full Access permissions, go to the following Microsoft website: