Has a past lover contacted you after many years?

I was contacted by someone who I dated ten years ago and he has expressed regret and still seems to be interested in me. I'm married but we never got closure and I feel confusing emotions. He was someone who I wanted to be with but life drifted us apart and we never got to say good bye. I just want to express unresolved feelings and move on but I'm scared because of the unforbidden thoughts I'm feeling. What do you think? Have any of you had a similar experience? Please share whatever circumstances!