code: def gut_message(message: Message) -> Message:
      
      wrapper = Message()
      wrapper.add_header('Content-Type', 'message/external-body',
                         access_type='x-spam-deleted',
                         expiration=time.strftime("%a, %d %b %Y %H:%M:%S %z"),
                         size=str(len(message.get_payload())))
  
      message.set_payload('')
      wrapper.set_payload([message])
  
      return wrapper
docs: Remove body from a message, and wrap in a message/external-body.