MailWasher Pro Enhances Spam Filter

Just as spam is getting smarter and more aggressive, so are the antispam weapons; FireTrust has updated its MailWasher Pro to use an advanced spam filter and also offer a subscription service that lets the application learn from other users' spam experiences.

MailWasher Pro 4.0 uses Bayesian filtering that can learn from experience how to better identify spam. MailWasher Pro is available now as a $37 download, which includes a one-year subscription to the FirstAlert service. FirstAlert costs $10 yearly after that. A free 30-day trial version is also available.

New Filter Tools

The Bayesian filter is an important addition, according to FireTrust. A Bayesian filter, named for English mathematician Thomas Bayes, examines an entire message--including addresses, subject, text, and attachments--for signs that it is (or is not) spam. The filter considers evidence for and against before making a verdict.

As with any spam filter, that verdict is occasionally wrong. But as you identify false negatives (spam that gets through the filter) and false positives (legitimate mail that does not), the program learns from its mistakes and improves.

With a FirstAlert subscription, MailWasher also learns from mistakes it makes on other people's PCs. When a FirstAlert subscriber reports a false negative, the message goes to FireTrust, where an employee decides if it really is an example of spam. If it is, the message is added to an online database. If you're also a FirstAlert subscriber, when MailWasher checks your mail the program references the FireTrust database to help make its decision.

Server-Based Approach

As with past versions, MailWasher Pro 4.0 does its filtering when the e-mail is still on your ISP's server, before it gets to your PC. You retrieve and display a list of messages in the MailWasher program without actually downloading them. It shows you which are likely to be spam, which contain viruses, and so on. After you've deleted the undesirables, you can go to your client and download your good e-mail.

This method has both advantages and disadvantages. On the plus side, it saves bandwidth because you download only the mail you want. What's more, because it displays a message's text without access to attachments, MailWasher provides a safe haven for opening questionable e-mail. On the other hand, the program does no good unless you remember to run it before downloading your e-mail.

Because MailWasher Pro doesn't integrate with your client, there's no issue of it supporting one client program and not another. The program works with standard POP3 e-mail, the same type used by Outlook, Outlook Express, Eudora, and just about any open e-mail client. It also supports AOL, IMAP, MSN, and Hotmail.