DMARC and Email Deliverability

In the past, the question of DMARC affecting deliverability was quite the debate. As DMARC grew to become an email authentication best practice and industry standard for phishing prevention, there’s little question that it affects deliverability.

When Google and Yahoo announced their revamped email sender requirements in February 2024, the fact that DMARC affects deliverability became immutable—deploying DMARC with an enforced policy strengthens email security and increases deliverability.

Because the terms can be misunderstood, let’s start by looking at the key differences between delivery and deliverability.

Delivery vs. Deliverability

An email sent from the sender to the recipient and reaches the mailbox provider (MBP) gateway server is defined as being delivered, i.e., it was not dropped at the gateway and/or it found the “destination.”

Once the email makes the gateway, there is another level, which is often overlooked. Where did it end up? Did it go to the inbox or spam folder? Was it declined because of blocklisting, overall sending reputation, etc? This is deliverability. As you can see, the concept of deliverability deals with the more refined results beyond that of an email simply being delivered.

How does DMARC affect deliverability?

DMARC instructs an email source, aka receiver, on how to handle emails that fail SPF and DKIM authentication from a specific source, but it’s up to the MBP to take action. By following best practices and being a responsible player in the email ecosystem, MBPs honor the DMARC policy and reporting instructions in the domain’s DMARC record.

As we saw earlier this year, Yahoo and Google have united in an effort to make inboxes safer and more secure by orchestrating an effort to require DMARC and other industry standards. Along with making mailboxes more secure, these requirements also result in improved deliverability.

How does DMARC benefit deliverability?

The results of implementing an enforced DMARC record have a positive effect on deliverability. Having valid SPF and DKIM authentication in place, with the identifiers aligned—the underpinning of DMARC—helps your email reach inboxes. Those records help MBPs identify you as a sender, and they also verify that you’re serious about your sending practices.

It is quite common for senders that do not have SPF, DKIM or both to not get their emails delivered or to have them throttled. There are many other components that factor into the decision of whether or not your emails are accepted, but authentication protocols are among the most important.

One of the other main benefits of DMARC relative to deliverability is the insight it provides into how your domain is being used. By using dmarcian’s DMARC Management Platform to closely monitor the feedback XML reports provide, you can quickly identify the right sources and which of your email streams need adjustment for proper authentication.

This tremendous benefit of DMARC is often overlooked, and senders should take advantage of everything they can, especially if there’s something that helps not only email deliverability, but overall security and brand reputation.

DMARC is no remedy for poor content and bad lists.

When you have DMARC deployed with an enforcement policy of p=quarantine or p=reject, you’re protecting your domain from spoofing and phishing as well as helping to prevent your outgoing email being marked as spam.

If spammers send forged messages using your organization’s name or domain, people who get these messages might report them as spam. This means legitimate messages from your organization might also be marked as spam. Over time, your organization’s internet reputation can be negatively affected.

Google

DMARC, SPF and DKIM are protocols that improve deliverability and reduce spam liability, but the content of the email and well-managed email lists also have an effect. Having your messages reported as spam has a consequential influence on deliverability.

How to improve deliverability

Following are some steps you can employ to improve your email deliverability:

• Obtain emails via organic list acquisition practices such as direct website sign-ups. Don’t purchase, rent or append email lists.
  
  
• Double opt-in is your friend. Use it to build a quality list and to comply with data regulations.
  
  
• Consider running your list through an email hygiene service to help trim out bad email addresses.
  
  
• Be sure to keep on top of CTR (Click Through Rates) and CTA (Calls to Action) to gauge if your content is landing with your audience.
  
  
• Segment your users so you are sending them the email they want to receive from you.
  
  
• Segment your sending streams to subdomains whenever you can.
  
  
• When possible, utilize a dedicated IP address so you control the destiny of your reputation.
  
  
• Pay attention to your sending cadence. Be sure to send regularly to keep your IP warm. MBPs don’t like irregular sending patterns (short high peaks and extended low valleys).
  
  
• Offer a clear, easy opt-out process for recipients.
  
  
• Use sensible subject lines and avoid typical “spam” signals, emotes and all caps. (e.g., FREE! MONEY! YOU ARE OUR GRAND PRIZE WINNER!).
  
  
• Utilize your pre-header space wisely to grab the reader’s attention and to hook them into your message from the jump. You are fighting for their eyes in the same crowded inbox as everyone else.
  
  
• Monitor your reputation in free MBP postmaster tools like Google Postmaster Tools.

And importantly, deploy and maintain a solid DMARC record. As we’ve established, benefits of implementing a p=reject DMARC policy, including stronger DNS-based authentication, aligned identifiers, brand protection, awareness, and more, help not only your deliverability, but also the overall digital footprint, security and presence of your organization.

Senders sometimes fail to implement a DMARC record because of their Email Service Provider (ESP). That might be because of technical constraints or simply because the ESP doesn’t feel comfortable guiding their customers through the process. Regardless of the reason, it’s important to note that our application and partner network can assist in overcoming those challenges by providing free tools and guidance to ESPs, as well as to our mutual customers.

Thanks for reading and let us know if you have any questions about DMARC and deliverability.

Want to continue the conversation? Head over to the dmarcian Forum.