Recently the spam level in my email exceeded the annoyance level by so much that I did a search for anti-spam programs. (Any theories on why it recently spiked? Has the same happened to you?). Lately I have been using Outlook under Windows 7 64 bit while waiting for the 64 bit version of Thunderbird, Shredder, to be ready for prime time. Outlook has junk mail filtering but the same annoying senders kept slipping through. The program I decided to give a try was SPAMfighter. I could not be more delighted, hence this recommendation. It's a nice, simple product that does exactly what it says it will. With cyberspace so full of hucksterism and promises for the future, that is high praise.
Give it a try. It's always a pleasure to give a sincere compliment.
http://www.spamfighter.com/Product_Info.aspUPDATE: As for the why, one thing I noticed is that the spammers seem to keep getting more sophisticated. Despite adding some of them to the Blocked Senders list again and again, they kept getting through, "From" the same senders. (Carl Peters and your low mortgage rates, you are officially recognized. You, too, Sears Kitchen Cabinets). They use different and apparently randomized sender addresses. Somehow SPAMfighter recognizes that they are sent from the same domain and casts a pox on all of them.