M. I also informed her husband, earlier, whose identity/email I was able to discover via email. I think he may have read my email to him and not have told her he knows as she was very concerned that he might find out. How do you know if someone is really leveling with you? I want to believe my husband but in the end...I feel like I will never really know.
LOL, welcome to Marriage Builders. Sorry for the reasons that bring you here. First off, the OW's husband probably doesn't know. Have you spoken to him personally? It is very typical that an OW will watch for and delete such emails so her spouse won't get it. You might want to call him personally - without warning - and discuss the situation with him.
It is also very unlikely that your H and the OW are telling you the truth about the affair. Even though you already know it was an emotional and physical affair [they kissed] it is unlikely they stopped there. Married people are in the HABIT of following passionate kissing with sexual intimacy. They would have no reason to have stopped. They continued their affair for days afterwards so obviously they weren't too guilty huh?
My suggestion would be to set up a polygraph and give him an opportunity to prove his truthfulness. He should welcome this opportunity to clear his good name and give you the reassurance you need. I would make the appointment, hand him a list of all of your questions [also ask about other affairs] and give him a last chance to come clean BEFORE the test. Tell him you expect him to pass the test, though.
This is one of the first steps. Next steps will be to affair proof your marriage by removing the conditions that led to his affair. I can tell you that traveling jobs are invitations to affairs so unless you want more of this, I would insist he get another job where he is not out of town. OR, make arrangements to go with him every time.
Please go read this thread and all the links and come back and lets talk:
Start Here First