My SO used to send me msgs like that when we had a fall out and he moved out for 6 months.
Used to say the most hateful, hurtful, meanest things to me. I literally would feel physical pain when reading them. It hurt that I hurt him so bad that he wished and thought the worst for and of me.
They were never threats though...just wishful thinking.
Just a piece of advice...you should be careful sending threatening msgs, emails or phone calls. Its something that can get you in alot of trouble if he one day gets sick of it and decides to get a restraining order on you. It'll be on your record and the judge will grant him the order as well as send you to some mandatory therapy or anger management classes. Which I don't think would be a bad idea, but you don't want it court ordered.
As much as it hurt reading his msgs...when the smoke cleared, all it showed me was that he was still hung up on me and was very much angry for it, so expressed it. Thats all your doing. Is showing him how much he still matters to you because you still feel these strong emotions towards him. Even if it is anger. Someone who doesn't matter, doesn't. You don't waste time and energy on them. And from what you've described, it sounds like you waste A LOT of energy on him.
Give yourself a break and focus on the cons of the relationship. On what drama and stress you're free from. Let him screw every skirt out there. Know that what you deserve is someone who deserves your time and energy and will appreciate it.
Let him realize that losing you was a mistake because you're a mature, independent, strong, capable woman. By you doing all this, you're showing him the exact opposite.
And learn to forgive him. It's not for him, but for yourself...to get well and move on.
Best of luck to you!
Simply-