Environment
Directory & Resource Administrator 9.1.x
Situation
After installing Directory and Resource Administrator (DRA) 9.1.x, the ability to search for Shared Mailboxes seems to be lost. The previous version of DRA was able to search for the Shared Mailbox, and searching for users seems to return fewer objects in either the 32bit client or Web Console. Checking outside of DRA, in AD for users may show a different number again. By searching for all objects in the Web Console, the result may be different than the one from the 32bit client. Checking in the environment shows that the Web Console is able to view the Shared Mailbox.
The Shared Mailbox is a mailbox that is accessed and used by multiple users, it is a special mailbox type in Microsoft Exchange. Users do not directly access the Shared Mailbox. DRA is able to manage these mailboxes in addition to other types such as the Exchange Enabled AD Users, Equipment Mailboxes, Linked Mailboxes, and Room Mailboxes.
Resolution
In order to view the Shared Mailboxes, open the Web Console and login as a user who has the proper powers to view the object. From here, click the "More" drop box to the right of the search field, and by "Search for" make sure that the Shared Mailbox is checked. Within the drop down box for "Search for" there will be numerous object types to search for. The search for all objects is simple, just open up the "Search for" box and click '"Select All". Now every object type will show up in the search, in addition now that the Shared Mailbox is selected in the search, any shared mailbox in the environment will show up.
Cause
On DRA 9.0.x or older, the Shared Mailbox object also managed the User Account that is associated with it. This can explain why searching in the 32bit client returns fewer objects when searching. With DRA 9.1 or newer, the Shared Mailbox ignores the User Account associated with it and only manages the mailbox itself. This is the reason why Shared Mailboxes are only visible when searching on the Shared Mailboxes and searching all objects from within the Web Console.
Additional Information
This applies to the REST Web Console installed via the DRA REST Installer from DRA 9.1.x.