BullGuard Spamfilter is a junk mail filter that uses a combination of techniques to keep your inbox free of spam.
The program integrates with Outlook, Outlook Express, Thunderbird and Windows Mail, for instance, and scans all your incoming emails looking for messages that it recognises as spam, or fraudulent phishing attempts.
Just like every similar program, Spamfilter will miss some junk - but that doesn't matter, as its users can help out. If you spot a spam email that's reached your Outlook inbox, say, just select this and click the Block button. Spamfilter will then recognise the message as spam and block it for all other users.
This can lead to problems if, say, some people incorrectly mark legitimate newsletters as spam, just because they can't be bothered to unsubscribe. Fortunately Spamfilter includes a Whitelist, which allows you to give the program specific email addresses or domains from which you'll always accept messages (they'll never be marked as spam). When you install the program Spamfilter will add all your contacts and the addresses of everyone you've emailed recently to the Whitelist, ensuring that their replies will never be accidentally moved to the spam folder.
There's also a blacklist, where you can add specific email address or domains that you want to be always marked as spam. This isn't so useful as a spam-fighting tactic, because spammers change their addresses all the time, but may still come in handy occasionally.
And on installation Spamfilter will train itself to recognise what are legitimate and spam emails, according to the messages that you receive. It will need two folders to achieve this, though, one containing only spam, one containing only real emails, so if you don't have these already then be sure to create them before you start the installation process.