Revenge rarely feels as good as you planned it would.

Planning it is the enjoyable part, because imagining the scene gives you all the control and the other person gets no lines. Carried out, it is brief, usually awkward, and it hands the moral advantage straight to whoever you were angry with. It also keeps you tied to them for exactly as long as you are keeping score.

Write down what you would do and leave it unsent for three days. Then ask what you actually want: an apology, some distance, or just to stop thinking about it. The third is usually available immediately and does not involve them at all.