Hugs, Sandrawg. Lots of good info here already. One quick note: NC = not contacting him and not looking at, picking up, answering the phone, etc., any of his attempts at contacting you. You wouldn't *get* to respond to his lies, denials, and cr-p, because you'd not be reading or hearing it. Ignorance can be bliss.
I've started using the tips that Lillamy posted, because I have to have contact with XAH because we have a son together. Those tips make it much easier.
I took the tip about sending his email to a special folder even further. The email address that XAH, his family and his GF use is now my junk address, used solely for him and his crew of enablers and victims.
I still write *to* XAH often to get out my f- you feelings, anger, hurt, to process through the issues in our relationship. If I hand write it, I burn it. If I type it on my computer, I delete it. I still get to express myself, but I don't set myself up for more cr-p from XAH.
Edit to add: I never type it from my email. I certainly do not want to accidentally hit that send button.