Challenge Response - Filtering 100% of spams

There are two ways you can filter 100% of spams. First, and least helpful, is tighten up your spam filter rules to the point where you get more false positives in your spam pit. This is pointless, because you spend more time searching your spam pit for false positives, than you would simply deleting spams from your inbox. The Art or Science page talks more about the fine line, or balance that must be struck in recognizing spam as spam, and ham as ham.

Another method which is gaining in popularity is the Challenge Response model. With a Challenge Response model, anyone trying to send you an email is challenged to verify that they are legitimate by providing a response. Lets say for example, that I use a Challenge Response system to protect myself against spam.

The first time you try to send me an email, it's delivery is put on hold, and an email is sent back to you. While you are expecting a reply from me, instead, you receive this challenge email asking you to click on a link. When you click on that link, you are verifying that you are indeed a real human, and not an automated spammer.

The next thing that happens, is your information is added to a database, so you will not be challenged the next time you try to send me an email. And, your original email to me is delivered to my inbox.

This is a perfectly workable scenario for personal email accounts, but is undesirable for a business. Imagine you're in business and rely on email as a communications channel with your customers. If you have little or no business competition, then you can afford to bother your prospective customers with a challenge response email system.

But if you're making any money in your business, chances are you have some tough competition. I for one, would become quite annoyed if my sales question were challenged, because the proprietor prefers not to deal with spam more intelligently. And unless highly motivated, I would enquire elsewhere for my widget needs.

For a more realistic approach to spam filtering please continue on to our Spam Filter Software section of this site. You'll find plenty of information on the different software filtering techniques and technologies that can be deployed on your mail server or filter.