How to get more emails delivered to your customers and prospects through SPF, DKIM and DMARC

Things have changed in the world of email deliverability. I can remember sending my first email campaign in 1996; there weren’t any problems getting an email to go through. Everybody received them. And if somebody needed what you were offering, there was a high likelihood that you’d hear back from them, too.

30 years later, email is still a staple—and vital—communication and marketing tool for many businesses. However, there’s also a cost to how easy it is to send email these days, including a never-ending supply of spam, email fraud, phishing scams, and more. As the use of email has grown, so too have the security vulnerabilities associated with it and associated inability to land emails in a customer or prospects inbox.

While companies want the benefits of email marketing, most are unaware of the protocols that could both protect their brand and also increase deliverability.

The first lines of defense: SPF and DKIM

Email authentication has evolved over time to combat one of the biggest threats to email users: phishing and spoofing, where attackers impersonate trusted senders. Two foundational technologies—SPF and DKIM—formed the earliest lines of defense in this effort.

Sender Policy Framework (SPF) was one of the first major authentication standards. It allows domain owners to publish a list of approved servers that are authorized to send email on their behalf. When a receiving mail server gets an incoming message, it checks the sender’s SPF record to verify that the email was sent from an allowed source.

While SPF helps verify the server the email is being sent from, it does not validate the visible “From:” address that users see. This means attackers can still forge the sender’s display name while passing SPF checks.

To strengthen authentication, the industry introduced DomainKeys Identified Mail (DKIM). DKIM applies a cryptographic digital signature to outgoing messages. Receiving servers use this signature to confirm two things:

1. The message truly came from a domain authorized to sign it
2. Its contents were not altered in transit

DKIM improved message integrity, but it also has a key limitation: the domain used in the DKIM signature does not have to match the domain shown in the email’s “From:” address. This mismatch allows sophisticated phishing emails to appear legitimate, even if DKIM passes.

Empowering better email authentication

Recognizing the need for a more comprehensive approach, industry leaders including PayPal, Google, Microsoft, and Yahoo collaborated to introduce DMARC in 2012. (Yes, you read that correctly: 2012. This protocol has been around for quite a while, but unfortunately, it’s not recognized or utilized by most companies. But I digress!)

The goal was to build on the strengths of SPF and DKIM while addressing their limitations and giving domain owners stronger control over how their email is authenticated and protected.

DMARC enhanced existing authentication methods in three major ways:

1. Alignment

   DMARC requires that the domain authenticated by SPF and/or DKIM aligns with the domain shown in the visible “From:” header. This prevents attackers from using valid SPF or DKIM results while spoofing a recognizable brand.

   For email marketers, this is critical. Alignment ensures that subscribers receive messages that are truly from your branded domain, improving trust and strengthening sender reputation.

2. Policy Enforcement

   DMARC allows domain owners to publish policies that tell receiving servers how to handle messages that fail authentication. These policies include monitoring, quarantining, or rejecting unauthenticated mail outright.

   For email marketing programs, this reduces the risk of fraudulent messages damaging your domain reputation, which directly affects inbox placement and long-term deliverability.

3. Reporting and Visibility

   DMARC generates detailed feedback reports from receiving mail servers. These reports show which sources are sending email using your domain, whether messages are passing authentication, and whether unauthorized senders are attempting to spoof your brand.

   For marketing teams, this insight is invaluable. It helps identify configuration issues, unauthorized platforms, and deliverability threats before they impact campaign performance.

Why DMARC is important to email marketing

When it comes to marketing, trust and credibility are king. DMARC is necessary for establishing trusted gateways for connecting with your audiences. With DMARC assurance, your mail is good to go straight to your recipients’ inboxes—meaning it’s recognized as genuine, non-counterfeit, and doesn’t trigger many of the email filters that exist today.

More emails in inboxes mean higher open rates, click-through rates, and of course, conversions, all resulting in a better ROI.

We could stop the article right here and this would certainly be enough to demonstrate how critical DMARC is to email marketing. But in a time of increasing online criminal activity, there are benefits beyond generating leads and prospects.

Brand and customer protection: An executive-level priority

You are in charge of an incredibly valuable piece of real estate: your brand’s reputation. And that reputation can—and sometimes will—hang on one single email. One breach can throw your most prized possession into the spinner.

DMARC helps maintain the integrity of your brand reputation and trust by protecting against email spoofing and phishing campaigns that could, at the very least, cause some serious stress. And these threats aren’t only coming from email addresses that are external to the company—we’re seeing increasing numbers of fraudulent emails coming from internal company emails, requesting payment authorizations and access to passwords and other sensitive information.

DMARC protocols also represent another filter for a company’s IT security infrastructure—one that could save an organization serious money. Losses from internet crimes in 2024 exceeded $16 billion–a 33% increase from 2023. As the threat grows, so does the need for heightened attention on security measures, otherwise companies could be forced to pay a lot of money to fix the potential problems.

SPF, DKIM and DMARC are essential components for marketing and security

SPF, DKIM and DMARC implementations are a major step forward for any company; it’s critical to successful email marketing and a broader security strategy. These protocols close the gaps that allow email fraud and phishing attacks to run unchecked, helping to establish authenticity, boost deliverability, and maintain your brand’s reputation.

If you need to get more emails delivered to inboxes—and want to elevate your overall security at the same time—get in touch! We’re here to help.