I have also had the problem sending to bigpond.com addresses this weekend. The outgoing email is eventually returned with Diagnostic-Code: smtp; 5.4.7 - Delivery expired (message too old) 550-'5.7.1 Connection refused. 60.241.0.14 is blacklisted in Invaluement RBL List. See http://www.invalument.com/removal' (delivery attempts: 0) Actually, the URL should be http://www.invaluement.com/removal When you put 60.241.0.14 into this website you get the response   60.241.0.14 is currently blacklisted on ivmSIP ... View more