Bring back an address you created earlier and deleted, e.g. to receive a password reset for an account you signed up with. Find it with search_deleted_mailboxes. It comes back empty (old emails are gone). Only your own addresses on domains still in service can be restored. Counts as a new mailbox for your limits. Returns a new mailbox id (mbx_…); the old id stays invalid, so use the returned id or the address.