First, it is a violation of the federal wiretapping laws to access another person’s email account. You should stop immediately! Further, if you have obtained those emails in violation of federal law, the information contained in them may not be allowed as evidence in any case against her.
I understand your emotional distress, and you may have a case for alienation of affections. To succeed on an alienation claim, you must prove that "(1) the marriage entailed love between the spouses in some degree; (2) the spousal love was alienated and destroyed; and (3) defendant