Is is okay to write an apology email to someone if they won't talk to you?

[AmyM]

I said some very mean things to this woman, and now she pretty much hates me. We were acquaintnaces, she is my husband's ex-wife. We had an argument, and I feel we both crossed the line. I tried to apologize sincerely to her over the phone and I cried and told her that I did not mean any of the things I said, she said she was sorry also. I feel horrible for what I said, because it was out of line, but my apology seemed to make no difference, even though she said she accepted my apology. I am not the type of person who has conflict in my life and as far as I know, she isn't the type either. I messaged her on facebook 2 days ago and asked about her and my husband's son and she blocked me. Do you think it is worth it to email her and try to let her know how awful I was and that my apology is sincere? This situation is creating so much tension, I want to move forward. Any suggestions as to what I could say to her???