Thanks, Martynas, but I guess I'm still confused. Do you mean that they don't use prefixes when you create new folders through them? I've created many folders through KMail (and some through Roundcube & Squirrelmail), and if I recall correctly all let me decide what the parent folder should be, and that's the prefix.
Or am I missing something?
And then do I really want to run the script? Will it make changes to already-created folders? Or only change the default parent folders for newly created folders?
Thanks in advance for helping me understand this.
Jeff