I'm looking for any assistance with this problem i'm having. Recently i purchased a Mac and am using Outlook and it has been working perfectly until yesterday when i received the following error message: 

nskntcmgw08p BigPond Outbound [OB105. Connection refused. 121.212.3.200 is listed on the Exploits Block List (XBL). Please visit http://www.spamhaus.org/xbl/ for more information.

As I have always used Windows and have always had an Internet Security software program on my computer I am at a loss as to what this issue is and I don't know anything about this 'spamhaus' website.

Can anyone please assist?  Any feedback would be very much appreciated :)

Cheers,

Anita