Why is it so important to ‘authenticate’ my e-mail?

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E-mail authentication is one of the most important ways recipients protect themselves from spam. The presence of authentication in e-mail—or the lack of it—is one of the key factors in determining if e-mail gets delivered to recipients.

And if the message is fortunate enough to get through the gate, authentication may decide where exactly it is delivered—to the inbox or bulk folder.

E-mail authentication is one of the most important steps marketers can take to increase deliverability and protect their e-mail sending reputation, which affects future deliverability. You can’t begin to increase response rates and ROI if your messages are not getting through to your targets.

Authentication may sound complicated, but it’s really an electronic signature on your e-mail tellin recipients that you are who you say you are. This is largely accomplished via SPF (sender policy framework) records, entries to your DNS registry and, in some cases, DomainKeys.

The specific technologies are changing, and some of the major ISPs have their own protocols for chosing a system of authentication. DomainKeys, for example, is used by Yahoo, while Hotmail and MSN look at SPF. One important difference between SPF and DomainKeys is that SPF authenticates using the IP address, while DomainKeys relies on the sending domain.

When a receiving server gets an e-mail, it performs a lookup on the sending IP address. For example, the server performs the following actions:

  1. E-mail claims to be from ABC Hardware;
  2. IP address is registered to ABC Hardware;
  3. SPF record/DomainKeys confirms this;
  4. Reverse DNS looks good;
  5. All is well, and the server is convinced that the e-mail came from a legitimate sender.
Spammers do not have authenticated e-mail streams. Phishing schemes will typically not make it through authentication checks. So without authentication, legitimate, permissioned e-mail can look like spam and be treated as such.

But authentication is not the only factor that impacts deliverability. Content, list hygiene and other components also play critical roles, especially for open rates, click-throughs and response rates.

However, without proper e-mail authentication, you’re starting out with an enormous hurdle in the path to optimal e-mail deliverability and campaign success.

Sarah Welcome is director of customer intelligence at IDG’s Corporate Services Group (

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