After you create the Exchange app, to protect all public folders, you must enable the All Public Folders group, and then assign the Exchange plan to the group.
From the navigation pane, go to Protect > Applications > Exchange.
The Exchange page appears.
On the Content tab, in the All Public Folders row, click the action button, and then click Manage > Change plan.
The Edit association dialog box appears.
Select a plan, and then click Save.
Click the Action button , and then click Archive.
A message prompts you to confirm submission of the archive job.
To view the associated public folders, on the Exchange page, in the row of the app, click the Action button , and then click Restore.
The public folders are shown as content of the Exchange app.