How can I give permission to all mail folders at once?

We have designated Generic Mail Boxes. There are folders set up in these Mail
boxes and I need to give permission for another user to use a Generic Mail
box and use all these folders set up in there.
In order to do this I need to go into each folder and give permission for
each individual folder one at a time.
Is there a fast way to give permission to all folders at once?
Any suggestions are welcome.
Thanks
Mary-Lou