The private information store consists of mailboxes that can belong to users or to applications. Mailboxes reside at the server running Microsoft Exchange Server. With the Microsoft Exchange Client, each newly created mailbox has four visible default folders (Deleted Items, Inbox, Outbox, and Sent Items). When approval is required before critiques are posted to the LitCrit public folder and available to the library Web application, a message with the critique that needs approval as an attachment on the message is sent to the Inbox of the designated approver.