http://blogs.msdn.com/tzink/archive/2008/07/12/the-problem-of-backscatter-part-8-why-is-it-so-hard-to-stop.aspxI came across the following diagram at this site, and it nicely summarizes the issue of backscatter spam: Getting a single piece of backscatter spam is one thing, getting dozens, hundreds or even thousands of them is a major problem.&#160; While spammersenCommunityServer 2.1 SP1 (Build: 61025.2)http://blogs.msdn.com/tzink/archive/2008/07/12/the-problem-of-backscatter-part-8-why-is-it-so-hard-to-stop.aspx#8725184Sun, 13 Jul 2008 00:22:57 GMT91d46819-8472-40ad-a661-2c78acb4018c:8725184a-foton &raquo; The problem of backscatter, part 8 - Why is it so hard to stop?<p>PingBack from <a rel="nofollow" target="_new" href="http://blog.a-foton.ru/2008/07/the-problem-of-backscatter-part-8-why-is-it-so-hard-to-stop/">http://blog.a-foton.ru/2008/07/the-problem-of-backscatter-part-8-why-is-it-so-hard-to-stop/</a></p> http://blogs.msdn.com/tzink/archive/2008/07/12/the-problem-of-backscatter-part-8-why-is-it-so-hard-to-stop.aspx#8730885Mon, 14 Jul 2008 08:27:22 GMT91d46819-8472-40ad-a661-2c78acb4018c:8730885John<p> I read an article about a new technology called ReceiverNet from Abaca. ReceiverNet technology characterizes each protected user based on the percentage of spam they receive and then uses those reputations to rate the incoming message flow. I changed my spam filtering system to Abaca’s Email Protection Gateway and &nbsp;it blocked Replica watches spam mails, Subpoena Phishing mails and many more. &nbsp;I found that Abaca’s ReceiverNet service has 99% efficiency in blocking spam mails and they guarantee their results. For more information, log on to <a rel="nofollow" target="_new" href="http://abaca.com/">http://abaca.com/</a>.</p>