Good, now that you've gotten THAT out of your system, get back to the good stuff, will ya?
I don't have much to add except that you MUST decide to end the snooping NOW. I am not convinced you have done that. I think you may still resort to it just to "confirm" things in the future. Please, don't do this. You saw why it's bad laid out for you in this last experience. You read that email and got all worked up because YOU laced it with all kinds of meaning that COULD have been totally wrong, as pointed out by all the posters commenting on THEIR take on it. Remember, YOU will project whatever feelings and thoughts you have at the moment on these things and no doubt make them into something that supports your worst nightmares rather than accept them as the byproduct of confusion and NOT something designed to hurt you.
Please, let that be the LAST time you snoop. Even if you don't trust him, trust yourself to make decisions and have patience WITHOUT any help (read:hinderance) from whatever you find snooping. You are strong, you CAN do that.