Marking sent messages read in Gnus over IMAP

When using Gnus, I want my sent messages to be marked as read in the remote IMAP folder. I use

;; mark Gcc (group Cc) messages as read
(setq gnus-gcc-mark-as-read t)

      

        
        
        
      

    

but that won't work. Does this only work for offlineimap? Is there a way to do this for the remote IMAP Sent folder?