If my user delete an e-mail or a complete e-mail folder from their mailbox I have to chance restore the deleted e-mail, folder to the real mailbox?

Maybe the shadow mailbox the good solution.
Can I create shadow mailboxes for my users?

The Postfix "always_bcc" option is not good for me because I can't restore an user's deleted subfolder from this "backup".

How can I restore after few days the deleted e-mail or a whole subfolder?

Thanks and sorry for my bad English.