Thank you again to everybody who has replied, and I wanted to just give an update, and answer a couple of questions hanging out there.

I did finally ask her about the email. Surprisingly she did not even focus on me reading it. Maybe she would have been more upset if I had been digging deep in her mail folders...but clicking on something that was on the screen when I sat down, she said was not that important compared to the issues the email was about.

I think she felt bad that I saw the discussion, but what I said was, basically: look, hurt feelings are not that big a deal, I can get over that. But it is a problem when she has severe issues w/the relationship that she can only vent to someone else, and cannot even start to address with me. Venting to friends is not that big a deal, look, I am not such a dope that I think it doesn't happen. But it becomes a problem when she is telling a MUTUAL friend this stuff, and hiding from me that this mutual friend now knows all kinds of unhappy things about our relationship, and has lowered the friend's opinion of me. And it is a problem when that friend delights in spreading gossip about others' troubles. (Hmm, maybe I am better off gaining some distance from this friend anyway.)

Anyway, this did not turn into a big fight, just more talking it through...and in fact she said she had some regrets after the emails, that she had chosen this person to vent to. And we agreed that venting is great but it can't be all there is, you have to work on the relationship if you want it to last.

Do I love her? Sure. Does she still love me? I hope so. Do I want the relationship to continue? Yes, because when we are functioning well, we support each other very well. I want to have both parents under one roof to raise the kids, because when things are bad for one or even both parents, it is still better than going it alone. I don't think the relationship is the only problem, and I think splitting up, as things stand, would just create two unhappy households out of one.