Choose Move Menu Setup from the Options menu.
The Move Menu Setup Options dialog box is displayed.
Select Local or IMAP Server to specify the server where the mailboxes are located.
If you select IMAP Server, type the server name in the text field.
Type the path to the mailbox under Path/Mailbox Name, then click Add.
The mailbox is added to the Move menu, as well as the Open Mailbox submenu of the Mailbox menu and the Copy To Mailbox submenu of the Message menu.
(Optional) Make further customizations:
To alter what is in the Path/Mailbox Name field once a mailbox name is selected, edit that field and click Change.
To delete a mailbox name from the scrolling list, select it and click Delete.
To display the mailboxes in alphabetical order, click Alphabetize.
To change the position of a selected mailbox in the scrolling list, click Move Up or Move Down.
Click OK or Apply.