Fast * Good * Cheap
The resurrected SpamBouncer Spam Filter is *fast*.
Over the years, as new features are added, software tends to become bloated. Bloated software spends more time doing less. This was true of the SpamBouncer by 2006, when I quit updating it. It's true of many spam filters today.
The resurrected SpamBouncer Spam Filter has been rewritten from the ground up. Much of its code came, not from the original SpamBouncer, but the Firehose spamtrap management system, which is designed to handle extremely high volumes of spam.
SpamBouncer Spam Filter is lean and mean.
SpamBouncer Spam Filter identifies spam effectively with very few false positives.
SpamBouncer Spam Filter gains speed and avoids false positives by identifying wanted email quickly. It further avoids false positives by relying on multiple checks, never classifying email as spam on the basis of a single check.
To improve its catch rate and speed, the SpamBouncer Spam Filter makes heavy use of industry-leading blocklists.
Finally, judicious use of content filters catches spam that initial sanity checks and blocklists miss.
OK, free. ;)
At least, the SpamBouncer Spam Filter is free. So are Linux, Postfix, and Procmail. You must still pay for a server and your Internet connection.
A VPS perfectly capable of running a personal mailserver costs around $15/month. Backups are quick; just make an image of the virtual instance. Hardware failures and lost data are things of the past.
If you prefer the added security of owning your own hardware, you can also install Linux, Postfix, Procmail, and the SpamBouncer Spam Filter on an old computer. Computers that crawl under Windows fly when running Linux. :)