IMAP clients such as Mulberry have the ability to mark a set of mailboxes as subscribed mailboxes. The IMAP client can send a specific request to the IMAP server to get the list of subscribed mailboxes. It is up to the IMAP client to decide how to present this subscribed mailbox list to you. Mulberry makes use of the subscribed mailboxes feature to allow you to create a set of mailboxes that always appear at the top of the mailbox list in each IMAP account, immediately below the INBOX entry. This is useful if you have a set of mailboxes that you frequently use and want quick access to in the server window.
The subscribed list appears in the server pane's mailbox list with the following icon next to it:
To add a mailbox to the subscribed list, select the mailbox and then choose the Subscribe command in the Mailbox menu.
To remove a mailbox from the subscribed list, select the mailbox and then choose the Unsubscribe command in the Mailbox menu.