I have recently noticed that one of Bigponds mail servers has been added to the SpamCop list. http://www.spamcop.net/w3m?action=blcheck&ip=18.104.22.168 has blocked Query bl.spamcop.net - 22.214.171.124 126.96.36.199 is mta10bw.bigpond.com This may better explain your email problems. Do you use a bigpong mail server as your outgoing? I have tried to contact telstra about this but I am not a customer of theirs so they are unwilling to help me. If what I think is correct, many thousands of people on the telstra network will be affected with their emails being bounced.