You might want to protect some mailboxes from deletion or modification except by the administrator. The following procedure describes how to do this.
If someone other than an administrator attempts to delete, modify, or rename a protected mailbox, the error message "mailbox is pinned" is displayed.
Set the store.pin configuration option by using the following format:
msconfig set store.pin mailbox1%mailbox2%mailbox3
where mailbox1, mailbox2, and mailbox3 are the mailboxes to be protected (you can use spaces in mailbox names), and @ is the separator between each mailbox.
In this example, the mailboxes specified in mailbox1@mailbox2@mailbox3 are not per user mailboxes, as in user/user1/Drafts. Instead, the mailboxes specified are for all users using a certain directory, such as Drafts. An administrator can therefore prevent users from renaming or deleting the Drafts or Backup folder for all users by running:
msconfig set store.pin Drafts%Backup