CHRISTIAN PARENTS of ESTRANGED ADULT CHILDREN Community Group
Estrangement makes it difficult to talk about with family, friends, neighbors and church members. Christians are NOT immune to broken families. Talk about your experiences with those who know how you feel and get positive support through your Christian faith...."In these last days difficult times will come, for men will be lovers of self...disobedient to parents,...

When our ES and DIL swore at us, my DH said that's it - no more communication and to this day he has not tried any connection with ES and gets mad at me if I say let's try one more time.
I am so sorry you are going through this.
It would be best if DH discontinues emailing. He is not asking for advice. The story of the prodigal son comes to mind.
I speak from personal experience on this. When DH and I decided to get married he was a Catholic and I was a Protestant - neither of us practicing at the time. His parents were devout old school Catholics. His mom went to church EVERY DAY. They were totally against my DH marrying a Protestant!!! That, to them was tantamount to a sentence of eternity in hell. Because of their religious beliefs they felt that they had to do what they had to do to keep their son from eternal damnation. His mom went so far as calling my mom and started out with...."Because you are Protestants I am sure that you are just as upset about your daughter marrying a Catholic. What can we do as concerned parents to stop this?" My mom answered her back with, "Well, actually we like your son and are looking forward to the wedding." His mom hung up very upset with my mom.
After that, she tried even harder with her son, my now DH, to get him to change his mind. She even went so far as to threatened not to go to the wedding if he went through with it - and she would have stuck to her guns too. My DH and I talked about it and he emphatically said that he would walk away from his parents if they continued and he was just as determined as they were. What stopped them from continuing their quest was his brother. He told him that his brother meant what he said and that they had better learn how to live with it or else lose him. They chose not to pursue it.
After we were married, they were civil and respectful to me although the never changed their beliefs - even when my DH did convert later on to Protestantism.
So, again, your DH has to realize that they are serious too and will cut you out of their lives if it continues. Sorry if this sounds harsh but I do speak from experience here.
If you still have some communication with ES and your husband stops the emails, ES might reconsider. You will all be in my prayers.