How DKIM Affects Email Deliverability

Ah, the spam filter: an email marketer’s nemesis. Finding our way through that filter and into the inbox keeps us email marketers on our toes—and away from too many exclamation points. But if you’re following email best practices (like the ones seen here) and still having trouble, you may need to approach the problem through a technical angle.

DKIM’s Role in Deliverability

Inbox deliverability is never a guarantee, but understanding how DKIM affects email deliverability can improve your chances of landing in the inbox rather than the spam folder.

DomainKeys Identified Mail, or DKIM, essentially allows a sender (that’s you) to associate your domain name (i.e., your website) with your email messages. DKIM serves as a digital signature in the form of a snippet of code on your emails and from your domain record. Once you send an email, the mail transfer agent (MTA) uses a public key to verify that the email is indeed associated to the domain. That association provides some assurance that the email actually came from the domain and hasn’t been altered or modified after it was sent.

This association is particularly important if you’re using a marketing automation platform or email service provider to send your messages—which you should always have in place if you’re doing any form of email marketing and hope to be CAN-SPAM compliant. We still hear of companies doing mass email marketing through BCC on Outlook, and it’s…terrifying to think of the consequences.

Why Does DKIM Matter?

DKIM belongs in the discussion of email authentication (more on that here). Email authentication ties into deliverability of your emails—in other words, if you prove that you are who you say you are, you’re more likely to end up in the inbox rather than caught in the spam filter.

Why, you may ask?

Not everyone uses email in a nice way, and your spam filter is on the lookout for those people. If your email isn’t properly authenticated, the spam filter may see your email as a potentially spoofed email. Email spoofing is a big problem for financial institutions or companies handling payments (think the PayPals of the world), as spoofers often pretend to send emails from the domain of a bank or payment service in hopes that the recipients will input their information on an invalid website.

If you don’t use authentication like DKIM, the spam filter could flag any email you’re sending through your marketing automation platform or email service provider. That happens not because you’re a spoofer but because they don’t know that you’re not a spoofer.

Another reason to have DKIM in place? Yahoo! requires DKIM to sign up for their Feedback Loop (where they keep track of spam complaints). That means anyone who doesn’t have DKIM set up isn’t capturing spam complaints at Yahoo!, and because of that, those email addresses aren’t being suppressed automatically. That could put you on the road to being blocked or blacklisted by Yahoo!

DKIM isn’t the only way to accomplish authentication, but it is one of the most complicated email authentication protocols available. It’s trickier to implement than Sender Policy Framework (SPF), which means that fewer senders have adopted it. But if you’re in a line of business—like finance or online payments—where would-be hackers have an incentive to spoof your domain, it’s worth the effort. And bonus—it’s something we help our emfluence Marketing Platform clients with right out of the box (no extra work for you)!

Yes, You Can Check Yourself Here

If you’re already using the emfluence Marketing Platform, you can run a spam filter check on every email before you send it:  

If you’re not using the emfluence Marketing Platform (yet), you can send yourself an email through your platform to a Gmail address. Once you receive the email, use the dropdown arrow next to the reply button to “Show Original.”

You could see any number of results, including:

Pass—email was verified, all is good.

Fail—signatures failed verification test.

None—no DKIM signature existed.

Policy—DKIM in place but didn’t meet the policy requirements of recipient.

Neutral—DKIM in place but configuration could be an issue.

Temperror—DKIM in place but a temporary error occurred.

Permerror—message couldn’t be verified because some part of the DKIM was missing or modified.

Naturally, “pass” is the one you want!

Need help? Give us a call or email us at expert@emfluence.com.