I'm not familiar, like you are, with all the contact she has has with and from other men.
I will tell you that in a marriage I find it incredibly dangerous to have opposite sex "friendships" that do not also include your spouse. So I would have big issues with my wife corresponding in any way with guys that I do not know. And an email that asks for nude pics would create a SERIOUS issue.
So I'm going to go with you on this topic and say that clearly she has some issues with handling relationships with other guys in an open and responsible way.
That being said, I'm not sure this is an issue that you can reach resolution on when you are already separated. Hell, my ex felt like once she stepped out of the house it was perfectly fine to bed the first guy who came along, marriage be damned.
This is a marriage counseling type of issue, and yeah, maybe one that you guys should have settled long before you were even married.
And as for the snooping, you know as well as I do that it both violates her trust and puts you in the position of being a fellow bad guy, as her response to you showed.
If you can't trust her without snooping, why would you want to be with her? You want to live that way the rest of your life?
At some point you have to let them go and trust that they will do the right thing. I know this is made harder by your previous experience, but you should never have entered a marriage with another if you were still reeling from the last betrayal. Now that you have, she deserves the presumption of innocence until she betrays that.
Bill
"Don't tell me the sky is the limit when there are footprints on the moon."