Just report them in-game using the report function. There's no point in sending screenshots from your computer because:
1. They can be doctored.
2. Screenshots don't actually show exploiting happening (for the most part).
3. The GMs have access to far more data than a simple screenshot. If you report the player within a relatively short time of witnessing the behavior, they can look at the logs and determine whether exploits were being used.
Use the Support Email system for that. Or, send a PM to a ZOS Moderator with the screenshot in it.
Note, I am not sure if the screenies are saved as JPG or Bitmap, not at my game to check. But if they are Bitmap, open it in something like Gimp or whatever and save it as a JPG
Enjoy the game, life is what you really want to be worried about.
PakKat "Everything was going well, until I died"
Gary Gravestink "I am glad you died, I needed the help"