To reach the Folder Listing screen, click "Setup » Default Domain/Servers » Public & Shared Folders » Folder listing/ACLs".
Displayed in this area is each public IMAP folder that you have created, the Per-user flags setting, and the Submission Address with which each one has been associated (if any).
To remove a public IMAP folder from the list, select the desired folder and then click the Remove button.
New IMAP Folder
To add a new folder to the list, specify a name for it in this control, set the Folder type, per-user flags, and Submission address options, and then click Create. If you want the new folder to be a subfolder of one of the folders in the list, prefix the new folder's name with the parent folder's name and a slash. For example, if the parent folder is "My Folder" and the new folder is "My New Folder," then the new subfolder name would be "My Folder/My New Folder". If you don't want it to be a subfolder, then name the new folder "My New Folder" without the prefix.
Use the drop-down list to designate the type of folder this will be: Mail, Contacts, Calendar, etc.
Store IMAP message flags on per-user basis
Click this check box if you want the folder's message flags (read, unread, replied to, forwarded, and so on) to be set on a per-user basis instead of globally. Each user will see the status of the messages in the shared folder displayed according to their personal interaction with them. A user who hasn't read a message will see it flagged as 'unread' while a user who has read it will see the status as 'read'. If this control is disabled then all users will see the same status. So, once any user has read a message then all users will see it marked as 'read'.
Use this drop-down list to associate a specific account with a shared folder so that messages destined for that "Submission Address" will be automatically routed to the shared folder. However, only users who have been granted "post" permission to the folder will be able to send to that address.
After specifying a folder's name and other settings, click this button to add the folder to the list.
If you wish to edit one of the entries, click the entry, make the desired changes to the Folder name or other settings, and then click Replace.
Edit access control list
Choose a folder and then click this button to open the Access Control List dialog for that folder. Use the Access Control List to designate the users or groups that will be able to access the folder and the permissions for each user or group.