Recursively batch rename files in Linux

If you’re using Kerio Mail Server (Kerio Connect) under Linux and you’ve moved around (using rsync or such) some mail folders, sometimes you’ll need to recreate the folder index, otherwise some email might not show up in your email program (Outlook,, Webmail).
The only thing you’ll need to do is to rename the index.fld files inside each (!) folder into index.bad.

Yeah, nasty. So: fire up your Vi editor and put this little script inside your store folder:
find . -name "index.fld" -exec sh -c 'mv -v "$0" "${0%.fld}.bad"' {} \;