[quote=kev374]Sometimes I feel I should respond with my point of view but other times I feel there is no point starting some sort of adversarial dialogue.[/quote]
Do not engage with her.
I agree with CE – the email should reaffirm that you made a good choice for your life by breaking up with her.
If you respond, you’ll get dragged back into the crazy zone – and no good can come of it. Do you expect her to accept facts and rational discussion? Based on her past history, that’s not going to happen. Continue to keep your distance and no contact.
Block/unfriend/whatever her on Facebook. No need for her to have access to your life.