I presume you are talking about the Exchange Deleted Items Folder. This answer is relative to that presumption.
I also presume you either mean that Empty deleted items selection is "greyed out" so you cannot choose it or you cannot select delete as a choice in that menu..
Exchange has a permissions entry for that folder. It must somehow be set wrong. You would need the necessary rights to deal with that exchange property (off hand, I do not know what rights would be needed for that, but it could be looked up).
I am able to do both of these without any special exchange rights.