Cloudmark ActiveFilter offers the only efficient technique for cleaning mail stores to significantly boost filtering accuracy

LONDON––June 23, 2008––Cloudmark, Inc., the global leader in carrier-grade messaging security, today puts e-mail security one step ahead of spammers by announcing Cloudmark ActiveFilter™, the first and only solution to efficiently clean up unwanted messages delivered to the service provider mail store, thus dramatically improving the user experience and freeing valuable storage capacity. With the addition of ActiveFilter to the company’s product suite, Cloudmark now delivers messaging security at every point in the messaging infrastructure––with Cloudmark Sender Intelligence at the edge of the network, Cloudmark Authority at the content stage on the mail transfer agent and with Cloudmark ActiveFilter monitoring the mail store.

The messaging security landscape has always been an arms race between attackers and anti-spam providers. In an effort to penetrate the inbox and reach their target audience, spammers and hackers are deploying extremely sophisticated techniques to evade spam filters. A current trend is to use botnets to send out huge volumes of rapidly-changing messages as quickly as possible. These bots can send millions of messages in under a minute. Given the intensity and speed of attacks, it’s no surprise that spam now constitutes more than 95 percent of all e-mail traffic and even with the most effective e-mail filtering in place, a small amount of spam will still find its way into e-mail inboxes––these are the messages spammers are banking on. For service providers, these messages are more than a nuisance––it is estimated that more than 15 percent of their mail store is consumed by spam messages alone.

Cloudmark ActiveFilter changes the spam game by eliminating the benefits of high-speed attacks. Cloudmark ActiveFilter continually monitors messages delivered to the mail store to determine whether any of them has subsequently been identified as spam. If a spam message got through initial content filtering and was delivered, ActiveFilter is able to act upon the message based on the user’s default policy. Cloudmark ActiveFilter increases accuracy to above 99 percent, which is significantly higher than the 80 to 90 percent accuracy of traditional rules-based solutions. Because Cloudmark’s cache of known threats is updated every 30 seconds, the entire process takes place in near real time and users with mailboxes in ActiveFilter environments will see dramatically less spam in their inbox.

“The entire ActiveFilter process is transparent to the end user, who only sees a cleaner inbox,” said Neil Cook, VP, Technology Services EMEA at Cloudmark. “Cloudmark ActiveFilter throws spammers, who have always relied on the fact that at least a few of their messages will clear e-mail gateways and filters and make it to user inboxes, a complete curveball. By eliminating spammers’ first mover advantage and speed of delivery to overcome ‘one shot’ anti-spam defences, we are literally changing the game and giving service providers the upper hand in the war against messaging abuse. With ActiveFilter, Cloudmark is now able to efficiently and accurately protect the inbox by removing newly-identified spam, viruses and phishing attacks before the user even sees them. The result is not only that subscribers are exposed to fewer damaging attacks, but also that they have a markedly improved user experience.”

Cloudmark ActiveFilter in action

What makes Cloudmark ActiveFilter particularly unique is its scalability. To even attempt the kind of remediation offered with ActiveFilter, traditional anti-spam solutions would need to extract every message from the mail store and run updated anti-spam rules across each message. With terabytes or even petabytes of data in a service provider’s mail store, that process would be unfeasible from a time and resource consumption perspective.

Cloudmark ActiveFilter is different because it does not need to re-scan every message to determine if it matches new threat fingerprints. Instead, Cloudmark ActiveFilter employs a “push” notification scheme whereby it alerts the message store to modify, move or delete only specific stored messages that have been identified as spam, without touching any of the remaining clean messages. This unique approach affords only minimal CPU, disk, MTA and mail store impact while reducing online storage by up to 20 percent.

This efficient process of re-checking messages and removing only spam is made possible by Cloudmark’s Advanced Message Fingerprinting technology, which is able to represent each message by a series of lightweight “fingerprints.” These fingerprints are unique representations of the message, but do not contain any actual content information. Cloudmark ActiveFilter caches fingerprints of messages that have been scanned and delivered to the mail store while continually monitoring for new fingerprint updates. If a match is found between a newly-identified spam fingerprint and a message in the mail store, ActiveFilter sends out a notification to the mail store to take action on that individual message. Because ActiveFilter does not need to re-scan every physical message, there is no delay in message delivery. Further, ActiveScan’s intelligent design ensures that messages are only removed from inboxes that have not been accessed by the user since the message was first delivered, ensuring that the action is completely transparent to the end user and has no impact on the user experience.

“The majority of missed spam today comes from fast-breaking attacks that circumvent spam filters,” said Bill Boebel, CTO of Mailtrust/Rackspace, a business-grade email hosting company and Cloudmark customer. “This negatively impacts the user experience and drives up operational and storage costs. Cloudmark's unique ActiveFilter approach closes this vulnerability gap by rapidly cleaning out the spam that made it past filtering the first time around.”

Cloudmark ActiveFilter will be generally available in Q3 2008 as an add-on feature to the Cloudmark Gateway edge MTA. To request more information or to trial Cloudmark ActiveFilter, please contact

About Cloudmark
Cloudmark, Inc. is a global leader in carrier-grade messaging security, delivering the most accurate, high-performance and comprehensive real-time spam, virus and phishing protection for fixed, mobile and social networks. Cloudmark patented solutions combine Advanced Message Fingerprinting technology based on innovative, highly efficient algorithms and a Global Threat Network consisting of trusted reporters in every country across the globe to provide security intelligence and filtering at all points of the messaging infrastructure. Cloudmark solutions protect more than 600 million mailboxes for the world’s largest service provider networks, including over 75 percent of major ISPs in the United States and Japan. Cloudmark's customers include Swisscom, EarthLink, Comcast, Tele2, Thus, NTT OCN and XS4ALL (KPN) as well as leading hosting providers, Mailtrust, domainFACTORY, Intergenia and others. Cloudmark is a privately held company headquartered in San Francisco with offices in London, Tokyo, Beijing and Hong Kong. For more information, please visit

Media contacts:
Cloudmark Team
Firefly Communications
0207 386 1571

Published on: 12:00AM on 23rd June 2008