I recently came across an issue with Exchange 2010 public folders where my users and even the administrators could not recover a deleted item from public folder deleted item recovery. This does not impact all public folder items and appears to be very random. A permission-based error is returned regardless of the level of security the user has.
According to Microsoft this is an object-level corruption issue within some Exchange 2010 public folder objects, and they will not be working toward resolution in the Exchange 2010 version. This is not an issue in Exchange 2013 Modern Public Folders. This article covers public folder recovery strategies to ensure that you can get your user’s data back for them.