DMARC Reject in 2025: No Longer Optional?

As we enter 2025, it’s clearer than ever that enforcing a strict DMARC reject policy is the way forward for email senders. In this article, I’m going to dive into how DMARC can protect your domain, and why companies should move towards enforcement ‘reject’ policy when it comes to authentication.

Table of contents:

1. The Growing Threat of Cybercrime
2. How DMARC Protects Your Domain
3. The Benefits of Enforcing a DMARC Reject Policy
4. Overcoming Challenges in DMARC Enforcement
5. Why DMARC Reject is No Longer Optional

The Growing Threat of Cybercrime

With the increasing rate of spoofed emails and sophisticated cyberattacks, email deliverability has evolved into a critical aspect of cybersecurity. Whenever I’m asked why Gmail and Yahoo have enforced stricter spam measures despite email authentication technologies being available for years, my answer points to the rising prevalence of advanced cybercrime.

Spoofed emails remain a significant threat, acting as a vehicle for phishing, malware, and ransomware. These fake emails, lacking proper SPF or DKIM authentication, often mislead recipients into believing they come from trusted sources. This growing threat has driven major mailbox providers to adopt stricter standards, placing email authentication front and center.

How DMARC Protects Your Domain

DMARC (Domain-based Message Authentication, Reporting, and Conformance) offers domain owners the ability to tell receiving servers how to handle unauthenticated emails. By publishing a DMARC record in the domain's DNS, senders can specify policies to take one of three actions: none (monitor only), quarantine (send unauthenticated emails to spam), or reject (block unauthenticated emails entirely). Read my previous Allegrow article on how to set up DMARC.

Companies often start with a "none" policy to monitor their email flows and identify gaps in their authentication setup which, while still keeping you compliant with the Google Sender Guidelines, is the least strict level of enforcement. 

DMARC Reports

DMARC reports, delivered as XML files, reveal email streams that fail SPF and DKIM checks. These reports often uncover both spoofing attempts and legitimate but misconfigured email streams. For example, internal teams using third-party tools like billing platforms or CRMs may inadvertently bypass proper email authentication setups. Reviewing these reports allows businesses to address such issues before moving to a stricter enforcement policy.

The Benefits of Enforcing a DMARC Reject Policy

The benefits of adopting a DMARC reject policy are significant. It ensures that only authenticated emails are delivered, protecting both senders and recipients. This safeguard not only improves email deliverability but also enhances a domain’s reputation, as mailbox providers can trust that all emails from the domain are legitimate.

Overcoming Challenges in DMARC Enforcement

Email deliverability is constantly evolving and can be challenging for those who are just beginning to understand its complexities. The latest Cybercrime Supply Chain Report highlighted how cybercriminals exploit email at scale, with phishing incidents rising nearly 40% and spam volumes doubling. The report emphasizes email’s dual role as both a vector for attacks and a frontline defense.

Why DMARC Reject is No Longer Optional

Moving to a DMARC reject policy demonstrates to mailbox providers that your domain is both trustworthy and secure. This step aligns with their efforts to combat phishing and domain spoofing while enhancing deliverability for legitimate senders. 

Moving further into 2025, adopting this approach is a necessary step in maintaining a secure and reliable email ecosystem. Enforcing a stronger DMARC policy sends a clear message to mailbox providers that your business is a responsible and reliable sender. This helps strengthen your domain reputation, reduce the possibility of your emails being filtered as spam, and ensure emails reach the inboxes of your recipients.

For assistance in ensuring your domain is properly authenticated and further opportunities to strengthen your domain reputation, you can book a free audit call with Allegrow.

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