Great anti spam system that accomplishes its mission without (and this is the most important) with a simple administration, intuitive and with a curve of adapted complexity. Special mention for your environment, one of the best in this type of applications.

Fast install. Fast scan. System Investigator tool for manually finding malware. It also promises protection against a wide range of other malware types.

I like that you can do a "quick scan" for when you are limited on time and suspect a bug, or a "Complet scan" when you need the entire system scanned. I also like that it can run in the background without slowing down your current software that is runnning.