We have a school that has deployed Exchange 2010. Now, because of the Nature of the school, we need to allow staff access to the students mailboxes and read email. The legalities of this have been covered off in the users agreement when they log in.
I have tried to allow this access with both the add-mailboxpermission cmdlet, and the add-adpermission cmdlet. Each to no avail. You can successfully impersonate the user in OWA with fullaccess on both, but attempting to read an email returns
" The item you tried to access no longer exists.
The item wasn't found. You or a delegate might have moved or deleted it using another computer or a mobile phone."