WARNING: If you have EarthLink, you will most likely not be able to forward emails to SpamCop using an their SMTP with an external client. I had opened a question on here:
After chat sessions, testing and experimentation, I found that they are blocking the outgoing messages. I just wanted hopefully save someone some pain and time in troubleshooting this. There does not appear to be a way around this, so it is time to change ISPs again.