I don't know what advice to give you, but I can tell you what happened to me. I was involved with OM over the internet. My H snooped and found my messages. He was very hurt. He confronted me about it. I was furious. So much in fact that I almost hated him. I know what I did was wrong, but I felt like he had violated my privacy. I know that sounds stupid, but remember the "fog" that the person is in and they are not rational. I have resented him very much for his snooping. One thing led to another until the next thing, he was going through my dresser drawers and telephone bills. It will turn you into a crazy person.
There are ways you can find out. And, as it has already been pointed out, we that are in the fog will underestimate the computer knowledge of the spouse. I certainly did my H! But, I am afraid that it will only hurt you worse in the long run.
It is not about what you feel should work in your M. It is about doing the work that gets the right results. Do what works!