Earlier this week I received an email from a rather forlorn customer asking, “I cannot stand the spam; what is a good spam blocker?”
Outside of the delete key, I have very few recommendations when it comes to “spam blockers.” Spam (or, “unwanted email”) is one of the Internet’s biggest problems, comprising almost 90% of all email sent. This may not be that big of a deal to the average email user, who might receive four or five spam emails per day; you simply highlight the junk, hit the “delete” key and go about your business. However, for large companies with thousands of employees, each receiving 100 bogus messages every day, spam email becomes a colossal waste of time and money.
Sadly, the antispam industry as a whole has not significantly improved since I wrote about the subject of content filtering in January of 2006. With a few exceptions, most antispam programs still struggle with a problem known as “false positives,” where they block good email, mistakenly deciding that certain messages are spam. A study by Brockmann and Co. (www.brockmann.com) shows that corporate America has lost a vast amount of money due to crummy antispam filters deleting messages from legitimate business contacts. At the same time, these lame programs allow Nigerian Scam (see www.scamorama.com) and Viagra spam through. That’s not exactly what I would call antispam security.
Just recently, at a specified time, I sent an important email to a client. Soon afterwards, they called me on the phone. “We haven’t received your email. Could you send it right away, please?” I replied that the message had already been sent, but that I would send it again, which I immediately did. Soon, there was another call. “When are you going to send your email?” they whined. At this point I was starting to figure out what was happening. “Check your spam email box,” I replied. Sure enough, there sat both of my messages. Good ole’ Norton AntiSpam had tagged my messages and sent them to the spam detention center. Sigh. Antispam offerings from McAfee, Trend Micro, Cox, AT&T, AOL, Microsoft, Apple, IBM, SpamPal and SpamAssassin can also give equally bad results.
Truth be told, most spam blocking programs don’t have the decision-making capability of a cockroach. That’s because they employ primitive artificial intelligence algorithms, called “filters,” with which they attempt to search for and block content containing predetermined objectionable words and phrases, a process often called “determination.” They then attempt to balance those words against the rest of the content and decide what to let through. Other filters are based on “white lists,” where you add email addresses to a list of senders from whom you wish to receive messages. “Black lists” are made up of the addresses of senders to whom you wish to deny access.
The best spam-filtering or spam-blocking programs use a combination of various filtering techniques, black lists, white lists and what’s called “challenge-response.” Because almost all spam comes from first-time senders, email from first-time senders is challenged, meaning that a “challenge” reply email is automatically sent to the originating email address. The originator must respond to the challenge by clicking on a link or visiting a website. Because spammers rarely or never reply to such challenges, challenge-response antispam schemes are the best in the business.
I recommended that my customer try the antispam service offered by a company called Vanquish Labs. I tried their service about a year ago and liked what I saw. Vanquish uses a combination of and variations on the above-mentioned techniques, along with some fascinating proprietary schemes. Other companies, such as Sendio and SpamArrest, also use challenge-response technologies, but I have not tested their products. So far, my client seems satisfied.
If you’d like to try the Vanquish product, visit my website and click on the “Vanquish” link. Let me know what you think.