Home  › Email › Email Marketing

MAP is Spam’s Simple Answer

  |  November 21, 2003   |  Comments

Steven Trupp says that current spam propogation measures are so primitive that a simple piece of software can solve most of the problem.

Steven Trupp, president of Bohemia, NY-based ICS Network Systems, has been observing the spam problem for some time. The company’s Mail Sentry Gateway service, which provides anti-spam, anti-virus, and anti-relay protection for corporate networks, processes a great deal of email traffic. Of necessity, it built its own spam fighting solution.

The company’s Mail Authentication Protocol (MAP) simply checks to see whether an email received at a server with the MAP milter plugin has a valid sender address. MAP validates the complete sender address at the MX host for the sender’s domain (or the domain’s A record host if no MX record is published).

On November 13, 2003, for a typical client, MAP rejected about 50 percent of the company’s mail (presumably letting some spam through). Of that, 31 percent was rejected because the MX host for the sender’s domain confirmed the sender’s address was false. 26 percent of rejected mail was forged as coming from Hotmail, Yahoo, MSN, or AOL. Another 26 percent was rejected because MAP could not connect to an SMTP server at the sender’s domain. 11 percent of rejected mail was blacklisted. The remaining 6 percent was on hold due to various errors, possibly benign, returned by the MX host.

Trupp says the mail catches the vast majority of spammers, who are not willing to include a valid sender address in their spam. "You cannot just use any fake email address appended to a valid domain to get around MAP," he says. He adds that spammers find that faking email addresses gets around a surprising number of filters.

Trupp says that traditional anti-spam measures are being foiled by proxy spam. Whether individuals are actually being paid to spam from their home accounts, or whether their home accounts and PCs have been taken over, he does not know, but he suspects the former. He is certain that a significant amount of spam now comes from home PCs running their own SMTP engine. The source IPs are clearly those assigned dynamically to individual subscribers by the large broadband providers, especially cable ISPs. This new source of spam is increasing at an alarming rate.

Because spam has changed from being a high-volume, single source problem to being a small-volume, multi-source problem, traditional blacklists don’t work anymore. Spammers no longer send from their own domain. "Spammers are soliciting people to work from home for money," he says. And in the current economy, he believes many would accept the offer.

MAP includes whitelist and blacklist features. Trupp says whitelists are useful, but users sometimes get frustrated with the blacklists. He says that spam coming off the cable networks has a valid, dynamic IP address. Blacklisting that IP address has little or no effect on spam. "Some customers get frustrated because there’s stuff they don’t want to see, so they add 800 IP addresses to the blacklist in the first week, and it doesn’t change much."

Nevertheless, some high-volume spammers still exist, and they will be frustrated by MAP. "Some spammers will send 1,000 emails in a single connection and use multiple connections. If the spammer has not provisioned an MX host that can actually receive a return email, each time he connects and I connect back to the MX host to verify an address, he waits 20 seconds for MAP to time out. Spammers face the same penalty that I’m incurring by checking them."

After implementation, Trupp advises customers to wait for several days collecting statistics on how the MAP engine handles the customer’s traffic. The MAP engine will probably be blocking some mail it shouldn’t.

Customers need to learn which mail types need special treatment. "If someone’s using Monster.com for recruiting, they may need to whitelist the address that receives the mail about monster.com because a lot of it will come from domains other than Monster, such as AOL."

MAP’s future seems to lie in becoming a component of another anti-spam solution, or a complement to several. Blocking forged mail pretending to come from large, known ISPs could be a business by itself, and is a useful idea.

Pricing and availability
MAP is available now directly from ICS as a milter plugin (pricing not public at press time) or as a component of the company’s Mail Sentry Gateway service.

The price for Mail Sentry Gateway is $250 for up to 50,000 messages per month. Trupp says that since the software relies on his servers, he has to charge based on his costs. "We’ve had no pushback from customers since we switched from per-user to per-message pricing, even from customers whose invoice amounts tripled."

ClickZ Live Toronto On the heels of a fantastic event in New York City, ClickZ Live is taking the fun and learning to Toronto, June 23-25. With over 15 years' experience delivering industry-leading events, ClickZ Live offers an action-packed, educationally-focused agenda covering all aspects of digital marketing. Register today!

ClickZ Live San Francisco Want to learn more? Join us at ClickZ Live San Francisco, Aug 10-12!
Educating marketers for over 15 years, ClickZ Live brings together industry thought leaders from the largest brands and agencies to deliver the most advanced, educational digital marketing agenda. Register today and save $500!

ABOUT THE AUTHOR

David Daniels

For more than 20 years, David has been an industry proponent. Direct Magazine said David is "one of the most influential experts in email marketing, if not the most influential." Co-author of "Email Marketing An Hour A Day," David has held senior level positions at Forrester and JupiterResearch, Apple, Anthropologie, MacWarehouse, Proteam, and retailers that dotted the early days of CompuServe. David advises many industry organizations including the OTA, DMA, eec, and has been a contributor to the Weekend Today Show on NBC. Learn more about connected marketing and download free research with registration here. Follow David on Twitter @emaildaniels and learn more at www.relevancygroup.com.

COMMENTSCommenting policy

comments powered by Disqus

Get ClickZ Email newsletters delivered right to your inbox. Subscribe today!

COMMENTS

UPCOMING EVENTS

Featured White Papers

Gartner Magic Quadrant for Digital Commerce

Gartner Magic Quadrant for Digital Commerce
This Magic Quadrant examines leading digital commerce platforms that enable organizations to build digital commerce sites. These commerce platforms facilitate purchasing transactions over the Web, and support the creation and continuing development of an online relationship with a consumer.

Paid Search in the Mobile Era

Paid Search in the Mobile Era
Google reports that paid search ads are currently driving 40+ million calls per month. Cost per click is increasing, paid search budgets are growing, and mobile continues to dominate. It's time to revamp old search strategies, reimagine stale best practices, and add new layers data to your analytics.

WEBINARS

Resources

Jobs

    • GREAT Campaign Project Coordinator
      GREAT Campaign Project Coordinator (British Consulate-General, New York) - New YorkThe GREAT Britain Campaign is seeking an energetic and creative...
    • Paid Search Senior Account Manager
      Paid Search Senior Account Manager (Hanapin Marketing) - BloomingtonHanapin Marketing is hiring a strategic Paid Search Senior Account Manager...
    • Paid Search Account Manager
      Paid Search Account Manager (Hanapin Marketing) - BloomingtonHanapin Marketing is hiring an experienced Paid Search Account Manager to...