Cox in Virginia is blocking it too. I remember things breaking on me. Not only did I have outlook problems, my scripts for the linux servers stopped working. Usually, I have the server email me via a script when it is done doing something, like rsyncing. I wasn't too happy about it. After debugging, I went to the website and searched what they did. Pure B.S.
After this protection against spamming, has it worked? I steadily get more and more spam myself.