There is a free and pro-version of CloudMark. By far, pro-version of CloudMark is the best spam blocker for Windows/Outlook. Easy to install & configure. The free version is limited, but helpful. The good thing is that I have never had CloudMark mark a valid email as spam. CloudMark has the best spam filtering technique.

This was originally ""I HATE SPAM"" - a GREAT program. After Cloudmark bought it out and re-named it it has not worked properly since. It repeatedly causes a fault in Outlook and Outlook will disable it. I can re-enable it and it works for a while, then it will quit working and I have to uninstall and reinstall it for it to work again. I have to do this several times a week and it is quite tiresome. When it works it is the best spam filter I have found. I just wish they had left ""I HATE SPAM"" alone!! This is a perfect example of ""if it ain't broke, don't fix it!!!""

Tried it for a day before uninstalling. Concept is good but execution is poor. Very slow on large folders--I archive regularly, but I still have thousands of emails in my main PST file. Also, if you choose to have spam moved to a Spam Outlook folder, there is no easy way way to empty it after reviewing. I'm looking for a button that one press would empty the folder--not implemented. I chose to unblock a Spam message. Ten minutes late it was still being 'examined.' Cancel did nothing--I had to use Task Manager to kill Outlook. This might be OK for light email use, but is definitely lacking for very heavy email use.