I attempted to help a friend clean up his system. Foolishly, I attached his system to my network to pull down updates, patches, etc. Three days later, I cannot send email from my company email server. After asking several questions, I was pointed to Spamhaus, who lists my IP as a violator. I've removed the system, cleaned all viruses, but I'm still on the list. HOW DO I GET OFF THE BLACK HOLE LISTING?