No reply was more powerful for me. It was me putting a boundary on myself and upholding my own core value of self protection from harm. So not replying was my conscious decision to stay safe. I believe it helped me to detach and work through the healing process more effectively than if he had just left me alone.
I can relate to this. It was my decision not to engage in madness any further and protect myself the best I can. After everything my poor ego went through, having an upper hand and the last word, sort of put my ego at ease, even though wasn't not much of a comfort.
It was my mind's victory over my feelings (which weren't good nor healthy for me). I am very impulsive person, who operates mainly on feelings and from the heart, so this decision was demonstration and victory of my will power, I had to work against my impulses, but today I'm glad I had the strength.