FRYE  I've been using this for a while with Entourage, and as others have said, it is simply the best protection you can find for your inbox. Between my service provider stopping spam at the source (so I never have to see it) and SS stopping the ones that trickle through, it is truly a time-saver. Like many people I have different email accounts for different purposes, so spam can and does get unruly. SS is the only solution I've found that makes a difference.

While it is difficult to set up (you definitely need the help guide), once done it basically runs on its own. I think the price is a little steep, and would recommend the developer charge $19.99, but I can also understand wanting to get compensated for the blood and sweat that went into creating the application. I think at a lower price point, they could sell even more copies, which in turn will take an even larger bite out of the spam inundating inboxes everywhere.  
(Version 2.7)