Preview spam and you'll get more

I described in the past month ways to prevent e-mail addresses on your Web site from being collected by "harvester" programs that feed spammer's lists (see E-Business Secrets issues from Feb. 26 and March 5).

You can solve an even bigger problem by keeping your business addresses from receiving more spam than they already get.

Other publications often warn you not to click the unsubscribe link of an e-mail message; if you do, it confirms your address and you'll get more spam. I'm convinced that this advice is dead wrong. Legitimate e-mail newsletters do honor unsubscribe requests, but most spammers don't honor them or use them in any manner, if their unsubscribe links even work.

Now there's a fascinating study that shows one of the real mechanisms that multiplies the spam your addresses receive. Out-law.com, a respected Web site maintained by British law firm Masons, ran an experiment that demonstrates this effect:

1. The law firm first set up numerous e-mail addresses that were unused except for being posted on various Web pages.

2. These addresses were soon "harvested" by software that searches Web pages for addresses. Spam messages began pouring in.

3. For the first two weeks of the experiment, the researchers did what novice Internet users do: They opened the messages that were received.

4. They found that 83 percent of the spam being received contained a coded "tracking" image. When the image was downloaded to be displayed in the message, it alerted the senders that a message sent to a specific address had been viewed. This is now the most prevalent mechanism by which spammers find "live" accounts, in my opinion.

5. Two weeks after opening the messages, the accounts that had been used received almost twice the volume of spam as before.

6. The researchers then began "bouncing" messages. To do this, they programmed their mail server to reply with a generic error indicating nondelivery. Only two weeks after taking this step, spam to these accounts decreased by 40 percent.

The bottom line? You can significantly reduce the spam that the addresses on your Web site receive by:

1. Not viewing messages that are likely to be spam.

2. Sending a "bounce" message to those messages that you deem to be spam.

It's important to note that the "preview pane" of Microsoft Outlook and similar e-mail packages downloads any images in your incoming messages. This activates the tracking codes in the same way as if you had fully opened the messages.

In my office, therefore, we turn off the preview pane of our e-mail programs before deleting messages that the From line or the Subject line indicate are spam. In Outlook, you can turn off the preview pane by clicking View, Preview Pane. In Outlook Express, it's View, Layout. (In various versions of Outlook and other programs, the menu placement may differ.)

It's trickier for you to send an "undeliverable" bounce to the senders of spam. Any mail server can do this, of course, but the hard part is integrating the controls of each user's e-mail program with this capability. With the volume of spam roughly quintupling every 12 months, I'm sure a button with this feature ("Delete and Bounce") will become a familiar part of all e-mail packages before long.