Anti-Spam Site Offers Earthshaking Results

Coffee: The IronPort site measures activity with a 'magnitude' value.

If your kitchen is being overrun by ants, you dont kill them one at a time. "You find their nest," say the engineers at IronPort Systems, who offer a similar approach to the problem of unsolicited commercial e-mail—or spam, as its more commonly called.

IronPort has launched a real-time e-mail monitoring site called SenderBase (, which offers a variety of methods for analyzing both the volume and source of e-mail being sent to addresses managed by several thousand participating ISPs, universities and corporate sites.

A top-level view of senders by domain name and IP address and other views by organization and by IP address groups of different sizes quickly reveal the patterns that a site administrator needs to devise reliable blocking rules.

The data on view at SenderBase is a byproduct of e-mail management tools such as IronPorts Bonded Sender Program, which allows a site to block any e-mail whose sender has not posted a financial bond against the sending of UCE. "All those sites pinging our servers, asking if an e-mail is coming from a Bonded Sender, give us floods of data on who are the high-volume e-mail senders," said IronPorts engineers when I spoke with them during the week that SenderBase made its debut.

The IronPort site measures activity with a "magnitude" value, patterned on the logarithmic Richter scale—no surprise, given IronPorts earthquake-country location. "Youre spoiling our fun," they said in mock dismay when I commented on the resemblance before they could point it out themselves. They went on, though, to say that an 8.5 mail sender may, indeed, be "shaking servers all over the world." As I write this, the only members of the 8+ club are three ISPs (Yahoo, AOL and Microsoft Mail), but seven "e-mail delivery" or "e-mail marketing" companies are at 7 or above. Now we can all know who they are.

When something is consuming a third of our bandwidth, only to be discarded when it arrives, its worth some effort to get it under control. Best of luck to the newly chartered Internet Research Task Force Anti-Spam Working Group (, but in the meantime, its up to the rest of us.

Tell me about your no-spam strategy at