It sounds as though you have set very clear boundries. That's terrific!
Can you set up a folder in your email and have all his emails automatically sent to it? It may help to not have them in your regular inbox. You mentioned he should only email you about your pending divorce, so I get why you need to check the emails even if he isn't respecting that particular boundary.
My ex kept saying he wanted a faster divorce, but he was too busy to file or some other excuse. I got sick of it, called my county family court and within 10 minutes, I found out what form to complete and had an appointment (free of charge) to get help completing the form. Once the form was complete, I paid $100 to file with the court. Taking control was huge deal for me, but it stopped my ex cold in his tracks. It was a massive boundary marker that very clearly screamed "you don't get to mess with my head and emotions anymore."

I hope you stay strong in maintaining the boundaries you set. I hope happiness keeps finding you.