Currently, during a file upload to an existing CC list, new contacts are added but there's no option to have missing contacts removed. Basically, we need a way to make the existing CC list be exactly what the upload file is. As it is, we have to delete the list and reupload it every time we want to "refresh" the list. Obviously, this new setting wouldn't be the default because uploading a file that only contains 10 names to an existing list that has 1000 would potentially delete the whole list and leave only the 10 names on the upload file. To explain another way, the goal is to keep a designated CC list “mirrored” and looking like an external list that we update via our in-house software. Then, uploading that list of names would both add and remove names accordingly to the CC list.