To have access to SkyVault
  Share sites using IMAP, the site(s) need to be added to your list of sites
  using Share IMAP Favorites. 
    - 
        Select IMAP Favorites in the Share
        My Sites dashlet on your My
        Dashboard page:
        


 - 
        Refresh your IMAP view to see the new sites.
        
You can see the site added to the IMAP Sites folder.