At some point she will be forced with a decision to make and I plan on improving myself for myself to help make that decision a no-brainer.
They pass email and text each other regularly. I am not monitoring any of it as it is not healthy for me.
At some point.... today's a pretty good day, it's as good as yesterday and probably as good as tomorrow but today is always good.
Mike what would make her change? What would it take for her to make the decision today?
"If you're still emailing the other guy while living with me and our children, you obviously have no intention of doing the right thing and working on the marriage, so you can have him but you also have to leave."
Then cancel the internet. Unplug the computer, disconnect it, box it up and put it in the garage or some other storage.
If she asks what the f!@#$%* you're doing, you tell her simply and without using more words than this:
"I've had enough, you won't disrespect me in my own home anymore."
Then get some boxes together, and start packing up her things. Tell her she has a few weeks to move out, tell her that once she finds a place you'll even help her load up a moving truck to put her stuff in it and tell her that she needs to sleep on the couch, you're not sharing your bed with her anymore.
And then tell her that you will both talk to your kid and let him know what's going on and that she will be moving out.
And then leave the room and reject her. If she follows you, get up and leave and go in another room. If she argues and brings up points about what you've done, you tell her "I was willing to work and improve myself, you apparently were not. I've decided I don't want this anymore, I want better."