I have exceeded storage space alocated to me on our institution's email. I
have manged to export email files in all other folders(including inbox) but
not from public folder. This is becuase outlook does not seem to permit
copying or exporting of files from the public folder.

Suggestions of making a copy of my .pst folder does not help becuase it does
not help reduce the size of the public folder of the new .pst folder.