How Receivers Think About Your Email

George Bilbrey
By George Bilbrey

I just got back from the Authentication and Online Trust Alliance Summit. It was really exciting to spend so much time discussing reputation and authentication with some of the smartest folks in the industry. If we are going to solve the spam problem and make inboxes safe for consumers and available to marketers, these are folks who are going to do it.

It was particularly exciting to see the interaction between the receiver representatives and large-scale marketers. One of our top clients actually said to my colleague Carmi Jones, “Now I get it!” – meaning, he now understands the interplay of reputation and authentication and how both contribute to inbox placement.

So, in the interest of helping you all “get it,” here’s some highlights of what’s on the minds of top receivers:

  1. They know what you did last Christmas: Receivers are watching mailers and they are using the data they have to make blocking and filtering decisions. If you think your reputation is tied to whether or not you are on a blacklist, you are way off. What are receivers watching? Complaints, unknown users, infrastructure set up and sending stability (that is, do you switch IPs a lot?). Content comes in last on the list and usually only after you pass the other tests. Moreover, some receivers are looking at this data from other receivers – a bad complaint rate at ISP B could very well impact your reputation with ISP A. There are both commercial and cooperative reputation systems that pool data across many receivers.
  2. Rendering is tied to reputation, too. Many ISPs are using reputation data to determine who gets to have images and links turned on and who doesn’t. In the case of Microsoft they are using our Sender Score Certified whitelist as the determiner – if you are on it (or if you are added to an individual user’s “safe list”) your images are on.
  3. Receivers are starting to understand the false positive problem. ISPs are starting to “get it” too and they know that “this is spam” doesn’t always mean spam. Microsoft is leading the charge here with the implementation of a new “unsubscribe” button for some email. However, this functionality will only be active if: (1) you are considered a safe mailer – meaning you are on the Sender Score Certified program or are on an end user’s safe list and (2) your email has the X-List-Unsubscribe header. For those of you really interested in this stuff – it’s interesting that Microsoft is now supporting the URL type of list unsubscribe header when before they had only been accepting the “mailto” type. If you aren’t sure what an X-List-Unsubscribe header is, talk to your tech team or your email service provider.

Okay, so now you get it – your sender reputation matters. Not sure how you are being viewed by the ISPs? Head over to and research your IPs and domains. The results will be illuminating and may shed light on your declining response rates.

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