If Spamfire is unsure about a message, it connects automatically to Matterform's filter server at Spamfire.net and performs additional tests. Spamfire.net maintains a database with thousands of known spammers. Matterform publishes hundreds of new filter updates every day. These filter updates are made available to you automatically, to keep your filtering accuracy high.
Make sure your Filter Update Subscription is current to ensure you get the best possible accuracy!
When a message is identified by a Remote Filter, it is considered "Definite Spam" and appears in the Definite Spam mailbox in the Spamfire Mail Window. You can use the Delivery Preferences to have Definite Spam messages trashed automatically so you don't even have to see them in the list.
The Remote Filters are used to auto-train the Bayesian filters. This greatly reduces the amount of manual training you have to do in order to get high accuracy in Spamfire.
See the Remote Filters Preferences Window to see how many Remote Filters are currently published.