How can I get rid of duplicate Sent, Draft, and Trash folders in my IMAP accounts? I use several IMAP accounts for e-mail, and, except for iCloud, all of them show duplicate folders for Sent, Trash, and Draft mailboxes: 



These duplicate folders are (generally) always empty, and seem to have no special status (e.g. the absence of the special icons used in OS X or iOS Mail):



But there seems to be nothing I can do to get rid of them. Is there a way to delete these folders or configure my IMAP accounts so that I at least don't have to see them in my iOS and OS X Mail clients?



Addendum: Here's what the folders look like through the hosts webmail interface:
Set Mail to use your operator’s folders by opening them and selecting Mailbox>Use this mailbox for>[folder function].
Move all messages from old folders to the new ones
Delete the old, now empty folders.