A copy of my message bounced back into my Inbox. What's going on?
Your Subscriber has an ISP with a broken mail system.
If a message is not deliverable, the ISP should return it to the sending computer (IE mail-list.com). Instead, they are returning it to you, the address in the From: line.
Mail-List.com computers did not see this bounced message. You may continue to receive this bounce until you remove that Subscriber's email address from your List.
Use these step by step directions to remove an email address.