I guess I am finally figuring out that the Serenity Prayer also applies here as well. If one tries to make peace and still your enemy insists on conflict, then you're no longer under any obligations to keep beating that dead horse, even if you know it would be best for everyone concerned, including your children. It takes two to tango, as they say.
Me, too. I struggled for a long time, and just recently am I giving up, deleting the nasty emails, and going totally nc. You can't co-parent with some people; it's just a reality. I'm not angry over that, more accepting than anything really. It sounds like you're working towards that also. Time for 180s.