Comments on: Spam blockers may wreak e-mail havoc

CNET News.com's Declan McCullagh writes that the growing use of technology to stop spam may also inadvertently prevent legitimate e-mail messages from reaching their destinations.

[ttul]

Wanna know how to make email useful again? Assured delivery solutions.

Email filters are great and getting better every day. SpamAssassin, PureMessage, Brightmail, Postini, Sophos... They all do a very good job at identifying spam and removing from my inbox. But what none of these products do a good job at is ensuring that I never miss an important piece of mail.

The next generation of "spam fighting" tools need to take a hard look at the problem of false positives -- as this article rightly points out. One company that seems to be doing something about it is MailChannels (www.mailchannels.com). MailChannels has developed a service that allows you to assign a different email address to each of the people with whom you or your organization communicates. And through a little innovation called "domain based aliasing", traffic sent to these addresses can be presorted at the network level.

What this all means is that traffic from important contacts (read: customers) flows to a "high priority" mail server which is configured to be relatively "loose" in its filtering, while traffic from unknown contacts flows through an extremely restrictive server, which applies the full litany of content and network level filtering techniques.

The result: Sure, filter out spam to my regular address. But when my important client sends me a message, you better believe it gets through -- even if they're sending from outer Mongolia via a Russian-controlled botnet.

Email will always suffer from the social problem that is spam. But the solution is not to build a better filter. That would be like throwing more police at the drug problem (and whether your're a republican or a democrat, you know that technique don't work). The solution is to add police AND build gated communities. And that's the MailChannels approach.

[Lerra]

Bayesian spam filter

Bayesian spam filtering seems to be the best way to go. I've had nice luck with Spam Bully http://www.spambully.com, which uses Bayesian as well as a few other techniques.

[cleanspam]

Spamfilter in uses a wide variety of local and network tests to identify spam signatures. This makes it harder for spammers to identify one aspect which they can craft their messages to work around.