Manipulate Expection message?

Currently I limit the file uploads with a hook and if a image is too large, it get’s resized. But I want to notify the user about this. All is working fine but is there a way to modify

  1. The headline of the expection? In this case “Fehler”, cause it’s not a error, only a notice
  2. the HTML or maybe insert a line break?

throw new Exception("My message here");

Nobody a hint?

I tried some things but couldn’t get it to work. That doesn’t mean it’s not possible, though.