The problem of Chinese folders

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help!
    I find the IMP cann't encode the Chinese folders correctly , when I
create new 
Chinese folders. And I cann't decode the Chinese folders correctly. I
checked the 
source code of IMP , and finded it use the imap_utf7_decode and
imap_utf7_encode
to encode and decode the name of folders.  But they cann't decode and encode
Chinese
correctly. Anyone can tall me how to let use can use Chinese folders.

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