How Will the Shift to Domain-based Reputation Affect Your Email Deliverability?

I recently had a chance to pick the brain of my esteemed industry colleague, Deirdre Baird. Deirdre is the CEO of Pivotal Veracity, Silverpop’s email deliverability partner, and one of the most knowledgeable people in the industry when it comes to getting your email successfully delivered to the inbox.

Specifically, I wanted to get her thoughts about an important and impending shift by ISPs away from IP-based to domain-based email reputation filtering.

Under the current IP-based reputation monitoring scheme, ISPs deliver or block your email based on the reputation of each individual IP address from which you send email. Under domain-based reputation monitoring, ISPs would assign the same reputation to all authenticated email from your company or domain, regardless of IP. (You can read more about it in this recent Direct magazine article.)

Can you describe that change and tell us when it will be in place?

“Currently, ISPs and spam filtering entities “attach” reputation to a particular email campaign—as is the case with “signature type filtering”—and/or a particular IP address. If, for example, a particular email creative is associated with high spam-complaint rates or a particular IP address is the source of high unknown-user rates, the ISP will then filter all mail like that particular creative or originating from that particular IP address.

“While both these methods are useful and will continue to be used, their efficacy is declining somewhat as spammers have learned to dramatically change the content and mail from thousands of hijacked IPs. The major ISPs are now moving toward a more holistic method of holding a mailer accountable for their actions. Specifically, ISPs are now moving to authenticated, domain-based reputation, whereby core filtering metrics such as spam-complaint rates, unknown user rates, and spam-trap rates will be computed at the domain level.

“This change is being tested now at AOL and Yahoo with DKIM-authenticated domains. It exists in some degree at Hotmail with Sender ID-authenticated domains, and is being considered by a number of other ISPs.

“While domain-based reputation will initially be used in addition to IP-based reputation at ISPs such as Yahoo, it will take a front-seat at AOL and, we suspect over time will become one of the most important methods ISPs will use to identify good mailers.”

What will it mean to Silverpop’s customers and other email marketers?

“The impact for mailers can be summed up this way: You will be held accountable—good or bad—for everything you do under your brand, that is, your domain.

“This is great news for legitimate companies who have consistently followed good mailing practices across their enterprise and developed meaningful relationships with their customers. It is not so great news for folks who have relied on a change in IP to escape the fall-out of an email append program that went south, or a purchased list, or a leap in spam complaints due to over-mailing.”

What percentage of an average B2C email marketer’s list will be impacted by this, and how will that change through the rest of 2009 and 2010?

“Yahoo is usually the first or second largest ISP on both B2C and B2B mailers’ lists. AOL typically ranks in the top 5 or 10 for B2B. Their combined market share on a typical commercial mailer’s list ranges from a low of 30 percent to a high of 70 percent.

“Mailers will begin to see the impact of domain-based reputation at AOL as early as this fall, and at Yahoo in late 2009 into early 2010. Additionally, Hotmail already considers domain-based reputation, although historically they’ve placed more weight on IP-based reputation. Comcast and Road Runner are actively researching how to execute a domain-based reputation system, but are not likely to have anything in place until late 2010 at the earliest.”

From a B2B perspective, do you foresee any of the popular corporate spam filters using this new approach?

“Absolutely. The large enterprise filters such as Brightmail, Cloudmark and Postini already attach a reputation of sorts to a piece of content. It is certainly plausible that the domain will play a role in their algorithms. However, as it is now, it will be a lot more difficult to isolate the impact of a domain’s mailing history from the impact of other factors—for example, content characteristics—used by the spam filters, whereas the ISPs tend to be more transparent in what caused a filtering issue. For instance, that the mailer has high spam complaint rates.”

My thanks to Deirdre for sharing her thoughts and expertise with readers of this blog. If you have any questions or comments, please feel free to share them below.