Outlook 2010: Can you search a shared mailbox and include subfolders?

Open the advanced find (Ctrl+Shift+F) and, using the browse option button, select the shared mailbox and then check the check box below Search subfolders.

http://answers.microsoft.com/en-us/office/forum/office_2010-outlook/unable-to-search-subfolders-outlook-2010/10b8f650-5a78-4bff-b527-3241b2ceb74e?msgId=d8146d4d-88bb-455b-94e1-b468cd70c32f

This solved the problem for me.

Answer 1:

Check if the option to search 'All Mail Items' is enabled.

1. Click inside the search window.
2. Once done you would find 'Search Tools' tab appear in the ribbon.
3. In the search tools tab, enable the option 'All Mail Items'.

Answer 2:

Disable the Download Shared Mailbox in the Advanced Settings of Outlook in Manage Cached Settings.