The Mailbox Settings page allows you to set the Mailbox Aliases - the list of simple names for foreign Mailboxes. You should use Mailbox aliases if you want to access foreign Mailboxes via IMAP clients that do not support the foreign Mailboxes concept. It is not recommended to use Mailbox aliases with more advanced IMAP clients or with the WebUser Interface itself, since they add unnecessary complexity to Mailbox management.
Type a simple Mailbox name into an empty field in the left column, type the name of a foreign Mailbox into the right column field, and click the Update button to create a Mailbox alias.
Your mail client software will list the created Mailbox aliases as well as the real Mailboxes created in your Account. You can open a Mailbox alias as you open a real Mailbox, and the specified foreign Mailbox will be opened.
Change the Mailbox alias name to an empty string and click the Update button to remove the Mailbox alias.