Hi RockyMtn - Thanks for your feedback. I wanted to give a few more details, just explain a bit more.
Shortly after Dday, I did reach out to the OM's BW to extend my sincere apologies and remorse, at a time/place/manner of her choosing, as I did not want to force my presence on her. My offer was not well received, and I completely understood, as my BH would not have reacted well to a similar offer from her WH at that time. I left it as an open ended offer. Her subsequent messages to me were not inquiries or questions, but more like a list of my shortcomings, all of the reasons she knew "why" I had an A and what I needed to do to fix myself. I accepted her need to vent to me, and never defended myself or made excuses. In fact, the only time I responded to her was to tell her I was 100% focused on my family and my BH, that I had no interest in contacting her WH ever again, and that she was welcome to contact my BH to verify that this was true (which she did).
In the following months, she continued to send me her "lists". They all followed a similar pattern. Again, she never asked me to confirm anything her WH had told her, and she never asked me to respond or contact her with a response. So I just stayed NC. After a while, I blocked her emails. I heard she had a 2nd Dday about 6 months later, and 4 more OW were revealed.
Late last year, 2 friends of mine contacted me to let me know the BW had contacted them, wondering if I had received a message she had sent me, because I had never responded. She also stated she "wasn't expecting a response". I hadn't received the message, but I asked my friends to delete it after I told them I knew the gist of her messages, and if it was along those lines, I didn't need to see another one. They both agreed it followed the pattern of her previous messages, and they did not forward it on to me.
Now, apparently she is telling a mutual friend that she sent me another message, with an apology, and is still puzzled why I am not responding. I have not seen this message, so I'm not sure it actually was ever sent. Even if it was, unless she specifically asked for a response or had questions for me, I probably would just stay NC, per our desire to stay NC with anyone associated with the OM. If she did want a response, I would definitely talk to my BH about it. He has not had positive interactions with the BW, so he is usually in favor of NC in all instances.
I know that's a lot of information, but I think it provides more context. Again, we live in a super small town (<5000), the BW has my phone #, my home address, knows where I live, what kind of cars we drive. She has many ways to contact me if she really wanted me to respond to her or answer her questions. I'm would be open to a one-time discussion, but again, no requests are ever included in her messages.
Do you think she is just looking for a "I received your message" type of response? I feel so sad for the BW for everything she has gone through, I am horrified at the damage I caused to her and her family, and I do not want to do anything that would add to her pain. From everything I read on SI (including the majority of responses here), NC = No New Hurts.