Comparing Real-World Performance of Anti-Spam Technologies
by: Jerry Liao
Just to give you an idea how spam is fast becoming a major problem for the enterprise – 12.4 billion spam emails are sent everyday. Converted to monetary value, the loss for corporation is about $9 billion and for non-corporate Internet users, it’s about $255 million.
What is spam? Spamming is the abuse of electronic messaging systems to indiscriminately send unsolicited bulk messages. And spam’s direct effects include the consumption of computer and network resources, and the cost in human time and attention of dismissing unwanted messages.
There has been a lot of anti-spam technologies and techniques being offered in the market today but how come spamming is still on the rise?
Brockmann & Company, a research and consulting firm, released findings from its independent, self-funded “Spam Index Report– Comparing Real-World Performance of Anti-Spam Technologies.” The study evaluated eight anti-spam technologies from the three main technology classes – filters, real-time black list services and challenge- response servers. The technologies were evaluated using the Spam Index, a new method in anti-spam performance measurement that leverages users’ real-world experiences.
When evaluating technologies with the Spam Index, lower scores represent the best performing technologies. The report finds that the best performing anti-spam technology is challenge-response, based on that technology’s lowest average Spam Index score of 160. The 160 score is 50% less than the next lowest average score of 316 achieved by hosted services, indicating that challenge response is twice as effective as hosted services for prevention of spam. The worst performing technology was filter-based ISP solutions, with a Spam Index of 442.
The study evaluated eight anti-spam technologies:
1. Challenge-Response-(Spam Index: 160)
This technology allows email from known senders to pass directly to protected users. In some cases, outbound email is monitored to add those addressees to the known sender list. First time senders, which include virtually all spam, are challenged with a reply email requesting that the sender reply to the message in order to assure the original email is delivered. Vendors in this category include Sendio and SpamArrest.
2. Filter – Hosted service-(Spam Index: 316)
Hosted email filtering services use the readily available processing power of Internet data centers. Vendors in this category include AppRiver, MessageLabs, MXLogic and Google/Postini, among others.
3. Filter – Appliance-(Spam Index: 349)
This class integrates software with a hardware appliance, tuning the package for optimal processing performance. Vendors in this category include Barracuda, Borderware, McAfee and Secure Computing, among others.
4. Filter – Commercial software-(Spam Index: 366)
This class tends to be virus filtering software with extended anti-spam functionality. Vendors that offer this class of anti-spam software include McAfee, Symantec and TrendMicro, among others.
5. Real-time Black Lists-(Spam Index: 367)
These reputation-based systems collect feedback from users to manage a ‘black list’ of known spammer IP addresses and domains. Vendors in this category include Commtouch, IronPort and Spamhaus, among others.
6. Filter – PC Email Client-(Spam Index: 386)
This spam filter is a feature of most email clients. Users can train their client spam filters to move or delete mail meeting certain conditions. Vendors in this category include Apple, IBM Lotus and Microsoft, among others.
7. Filter – Open Source software-(Spam Index: 388)
This technology is frequently configured to work in conjunction with PC email client filters. The server adds ****SPAM**** to the subject line so that the client filter can move the message into the junk folder. This class of software includes projects such as ASSP, Mail Washer and SpamAssassin, among others.
8. Filter – ISP-based-(Spam Index: 442)
Offered by most email hosting service providers, this anti-spam technology provides some form of anti virus and anti-spam filtering for hosted domains. The study showed that this was the least effective solution.
Developed by Brockmann & Company, the Spam Index is based on the number of spam messages that users receive in their inboxes, messages that need to be resent and good messages trapped by the anti spam system (false positives). Most distinctly, the Spam Index takes into account the time users spend managing spam including deleting junk messages, scanning anti-spam folders and investigating the authenticity of messages that appear legitimate.