SpamSafe is fairly unique as it relies heavily on "Regular Expressions" to Filter Email. It comes with ready-to-use Filters and RBL s (Remote Blacklists) Filters already installed. Each and every Filter can be Enabled and Disabled on the fly. The commercial version (FREEWARE version available) is marketed as Rentware (The price reflected is the monthly fee). When you consider how quickly software goes out of date Rentware is the perfect option. No Capital outlay. no upgrades to buy, just a small subscription. You will NEVER be asked to pay "a little extra" to get the next release. The entire application is about 2MB in size.