A colleague's Microsoft Exchange email account got corrupted so we needed to delete her account and set it up again.  We backed up her current account in both PC (pst) and Mac (olm) formats and everything has been fine with the new account and restoring the backup emails apart from the calendar items.

Whenever we reintroduced the calendar items they come in as copies and are no longer editable/under my colleague's control.  We have tried opening, importing, drag and dropping them.  We have separate olm and pst files for the calendar items so can focus just on these but can't find away around it.

Happy for either a PC or Mac solution.

Many thanks for any guidance.