Spam filters that work

I wrote a piece on my blog on Tech Republic today about an RSS feed reader that I like and use. I wrote it in response to a piece from Gene Marks in Business Week claiming that no business owner uses RSS feeds after they've tried them. I tried to politely disagree.

He made some other points in his article with which I disagreed but I didn't want to overload my readers on Tech Republic with too many disagreeable points. So I'll bring it up here. Gene also claimed that no spam filter works. I don't think he has had a lot of experience with spam filters, or at least not good ones. No business in the world should be without one.

There's no way I can endorse his recommendation that employees sort and delete their spam as it comes in. That's ludicrous for any business today that has more than a few employees or that has an email address that has been around for more than a few months. What a tragic waste of time for the employee and a loss of productivity for the employer.

Maybe the business I work for is a little bit larger than his small business experience. We have over 100 mailboxes and receive over a half million pieces of email each month. Guess what? 97% of that email is spam. We could not function without a decent spam filter. Of course no filter is 100% effective but it cuts it down to a manageable one or two pieces.

I've written previously about our success with Commtouch but I have also been somewhat pleased with Cloudmark for the really small business who has litle or no IT budget. But for a professional MS Exchange environment go with Commtouch or Postini or some other outside service to clean your mail before it gets to your employee's mailbox.

What do you think? Is there a limit to the amount of spam that employees will tolerate before productivity starts to really decline and morale suffers?