I have found that men do not sit and percolate about an email response. They either write back right away or they don’t ever write back. That’s how I surmised your ex would not ever write back. Rarely you will get a man who ponders something and writes you later on, but in your break up case, I didn’t think it would happen. He was not classy enough to apologize and he certainly did not want to discuss his bad behavior.