Optus, how about you clean up your act a bit? One of your outgoing mail servers got in trouble again:
I think being listed on the Backscatterer RBL is fairly common for an ISP however its not used by many hosting providers that I am aware. When listed by Spamhaus or Spamcop then you really do have problems as they are normally on by default with most WHM cPanel installations and subsequently many hosting providers use them.
At least .246 got delisted from bl.mailspike.net, so perhaps whinging here helped to some extent. Optus should periodically check their outbound SMTP IP addresses against the most commonly used blacklists and set some alerts if they get blacklisted. Suggest checking at least against:
Yes possibly someone was listening or they go through the motion of delisting mail servers on their own. One issue is that many RBL's wont delist an IP especially if its been reported more than once. I do recall that Spamhaus and Spamcop both have automatic delisting the first time around and that's one of the reasons they are more popular than others.