Telstra BigPond (or BigPong as some would have it) is notorious for being blocked. Some have suggested this may be an error but last time I looked there was a *huge* list of their servers "known to SpamCop" (see under):
http://forum.spamcop.net/forums/index.php?showtopic=650From my own experience, I cannot recall a single instance of spam from this source - but I have an identifiably American ISP and receive almost only spam targeted at North America (lucky me). Anyway, good luck and remember, employment with BigPond's helpdesk is keeping the little devils there off the dole queue. You can presumably work around the block by getting yourself/daughter a free account with HotMail or Yahoo or whatever and forwarding in two stages (if they don't block BigPond too - otherwise copy & paste).
Incidentally, I've heard BigPond is blocked from some IRC services too. I don't know if this is actually so, or whether it is as a result of SpamCop's BL being used a little more freely than it was ever intended but I wish I could be a little more confident they didn't deserve at least *some* of the treatment they get - though it is not as if I'm a Telstra shareholder ;-)
Late addition - Oh yes, I shouldn't think you will find BigPond blocked all the time - keep trying, but also please let them know all about your problems.