From: t on
We have a Powerpoint 2007 document which some former employee in our
office created before he left a year ago. Now, we need to open it and
when we try it, the document mentions you don't have read permission for
this. Do you want to obtain permission from that person's organizational
email address which does not exist as he has left.
We tried to contact the former employee who does not have that document
with him at present.

Is there any way we can open the document? I don't know enough about
Information Rights Management(IRM), but understand like PGP it is a tool
to restrict permissions.

Any advice would be appreciated.