eBay is hundred percent correct on their statement. Live.com.au uses Hotmail addresses. So if you send to someone at live.com.au, then Hotmail processes the message, and causes bounce backs. Live Mail is connected to Hotmail. Hotmail is causing all the emails I receive from eBay to bounce back, so I ditched my live.com.au account and switched to an outlook.com account, and every email from eBay appears to be getting delivered there.