Secrets & Lies: ISP filtering

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B-to-b marketers may not think ISP-level filtering affects them or their marketing programs, reasoning that if you’re marketing to another company, you probably don’t have to worry about getting past AOL’s or Yahoo’s filters. Think again, said Deirdre Baird, founder and CEO of Pivotal Veracity, a provider of e-mail delivery optimization solutions.

“Many b-to-b marketers use hosts for their e-mail. Yahoo is one of the largest business hosts out there,” she said. “Marketers set up their domain and mail system under these hosts, so even though you, as a marketer, are sending to a company domain, your message is undergoing the same filtering as someone sending to a consumer with a e-mail address.”

Baird’s company this week released a new report (“What’s in Store at the ISPs: 2009-2010”) that details major changes in ISP filtering technology. BtoB asked her to identify one little-known e-mail marketing secret as well as one commonly believed “lie” on the topic.

Secret: Large ISPs are augmenting their IP-based reputation systems with domain-based reputation systems using DomainKeys/DKIM authentication.

Whenever someone sends an e-mail, the recipient server checks the sender IP address. If it is on a black list, that e-mail is potentially marked as spam and never reaches its recipient. As most marketers know, you don’t need to be a spammer to get lumped in with them. If you’re on a shared server, for example, and someone else using that IP address has been spamming, you’re labeled a spammer, too.

With DomainKeys/DKIM authentication, that changes, however. The server matches the domain with specific IP addresses that you preauthorize. It knows that an e-mail coming from “” should have a specific IP address or range of addresses. If it doesn’t, that e-mail is handled in the way you have specified, Baird said. “This is a huge win for small and midsize marketers who might share a host or add IP addresses as [they] grow,” she said. “You can use it to prevent phishing, as well as improve deliverability.”

Lie: When you use DomainKeys/DKIM authentication, any phishing or spamming activity reflects on your brand.

If you set up authentication correctly, you can actually block spammers and phishers from getting through to your customers and prospects with fake messages. When you set up your account and specify which IP addresses should be associated with your domain, you’ll also have the ability to tell the ISPs and mail processing services such as Postini or Spam Assassin what to do with e-mails that aren’t originating from your company. Unfortunately, some marketers set their accounts so that such e-mails get a soft bounce. This is the wrong move, Baird said. Make sure you specify that e-mails sent from IP addresses that don’t belong to you get a hard bounce, she said. “From the perspective of a spammer or phisher, I can pretend to be your company all day unless you set it up for a hard fail,” she explains. “Those hard bounces will not affect your reputation at all. Unauthenticated e-mails do not affect your unknown user rates or spam rates. Only mail that passed authentication goes against your metrics.”

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