Married ex's emailing - spouses know - now fight with ex?

The same thing happened to me. What I did was send a long email back telling him not to reply to this but layed it all on the line about how I felt being treated that way etc. To cut a long story short about 6 months later I got an apology email and I left it like that. It is hurtful to know that someone you thought you had a bond with didn't really care enough.