Listen to confused; she speaks words of wisdom.
I read your older posts and I would advise you not to talk to the OW. She will not tell you the truth. Your H and this low life of a woman have already discussed and have come to an agreement what to tell you just in case....don't waste your time.
Do tell her H though. He must know. I think only FED EX allows addressees to sign if that is what you ask for.
You gave him more that enough chances to break it off with her. I agree with the other posters: they are still having an affair and they have taken it underground. To tell you the truth, even if he gives you all his passwords, I would not trust him. It would be easy for him to open up an new email account only for the two of them. How would you know? I do not trust him; sorry.
Do the 180. See an attorney to find out your rights in your state. Tell him nothing of what it is you are doing.
If you can afford a PI, do hire one. Since these two work at the same place, it will not cost you much. All the PI has to do for a week or so, is to watch their work place at noon and also after 5pm or whenever work is over. He needs to see if your H and this woman go out to lunch together or for drinks after work or for a 'quicky' in his /her car since they have already engaged in such behavior. Ask the PI for a report, a DVD and pictures.
Make duplicates of everything and hide one set. Then confront H but be prepared for more lies, trickle truth and denials. If he destroys your copies, no big deal..you'll have the duplicates. If you have a trusted friend, give her the duplicates so he does not find them; otherwise make sure you hide them where he could not find them however hard he looks for them.
You are NOT unreasonable. R cannot be achieved with these two seeing each other every day. It is impossible.
Do they have an Ethics dept where H works? Why don't you call them and report them? You can do it anonimously. He could be fired; heck !! Both of them could be fired!!!
If H accuses you of reporting them, play dumb, turn it around and get angry at him for even thinking that you could do such a thing. Then walk away. Don't engage in any more conversations with him on the subject. Think of it this way: Mission accomplished; he does not work with her any more.
Unless you move out of state, regardless of where he may find work in town, they could still be involved together...