DMARC Reject vs Quarantine: What's the Difference?

When implementing DMARC to secure your organization's email communications, you often evaluate two main policy options: reject and quarantine. Understanding the differences between these policies is crucial for achieving optimal email security while avoiding disruptions in legitimate email delivery.

In this article, we'll explore what DMARC reject and quarantine policies are, how they differ, and when it's best to use each one. Let's dive in and help you determine the right strategy for your email authentication setup.

What is DMARC?

Before we discuss the differences between DMARC reject and quarantine, it's essential to understand the basics of DMARC (Domain-based Message Authentication, Reporting, and Conformance). DMARC is an email authentication protocol that helps domain owners protect their domains from email spoofing and phishing. It works by aligning SPF (Sender Policy Framework) and DKIM (DomainKeys Identified Mail) results and providing instructions on how recipient servers should handle suspicious or unauthenticated emails.

DMARC policies can be configured with three main actions: none, quarantine, or reject. Let’s focus on the latter two policies—reject and quarantine—and understand how each impacts your email security.

DMARC Reject Policy

The reject policy is the most strict setting available within the DMARC framework. When a domain owner sets their DMARC policy to reject, it tells receiving email servers to refuse any emails that fail the DMARC checks. Essentially, if the message cannot be authenticated, it will not be delivered to the intended recipient.

When to Use the Reject Policy

Using a reject policy is ideal when you have fully optimized your SPF and DKIM records and have complete confidence that legitimate emails are being authenticated correctly. This setting provides the highest level of security by blocking all unauthorized emails, which minimizes the chances of email spoofing and brand impersonation.

However, moving to a reject policy should be done gradually to ensure that no legitimate emails are accidentally blocked. It’s recommended to start with a more permissive policy, such as quarantine, and monitor your DMARC reports until you are confident your authorized email sources are properly aligned.

DMARC Quarantine Policy

The quarantine policy is a less strict approach compared to reject. When an email fails DMARC validation with a quarantine policy, it is not outright blocked. Instead, the email is delivered to the recipient's spam/junk folder. This gives the email a "second chance" to be viewed by the recipient, albeit not directly in their inbox.

When to Use the Quarantine Policy

Quarantine is a safer option for organizations that are in the early stages of DMARC implementation or when they are still ironing out authentication issues with legitimate email sources. The quarantine policy allows domain owners to test and optimize their authentication settings while reducing the likelihood of incorrectly blocking legitimate emails.

Using quarantine helps build confidence that your SPF and DKIM records are accurately set, allowing you to identify any potential delivery issues before moving to a stricter reject policy.

DMARC Reject vs Quarantine: Key Differences

Aspect	DMARC Reject	DMARC Quarantine
Action on Failure	Rejects email outright	Moves email to spam/junk folder
Level of Security	High security, no chance of delivery	Medium security, limited delivery
Ideal Scenario	Optimized DMARC implementation	Testing phase, addressing alignment issues

The key difference between reject and quarantine is how unauthorized emails are treated. With reject, unauthorized emails are never delivered, while with quarantine, unauthorized emails may still be reviewed by recipients in their spam folders.

Choosing the Right DMARC Policy for Your Organization

Selecting the appropriate DMARC policy depends on where you are in your email authentication journey. If you're just getting started or want to minimize the risk of incorrectly blocking legitimate emails, the quarantine policy is a good choice. It allows you to gather insights and adjust your settings based on real-world data.

On the other hand, if you have a well-optimized setup and have verified that all legitimate email sources are compliant, the reject policy provides the best protection against email-based attacks.

It's important to utilize DMARC reports to track your email flows, troubleshoot alignment issues, and build confidence before transitioning to a stricter policy.

Ready to Secure Your Domain?

Understanding the difference between DMARC reject and quarantine can help you implement the best policy for your email infrastructure—leading to fewer threats, increased email security, and more control over your brand's reputation. If you're interested in evaluating your current email security posture, why not try our Email Security Score tool? It’s a simple way to see where you stand and what improvements can be made to enhance your email security.

Strengthen Your Email Security Strategy Today

Choosing between DMARC reject and quarantine depends on your current state of email readiness. By gradually moving from a quarantine to a reject policy, you can build a solid email defense system that protects your brand and your customers from malicious activity. Take the next step towards robust email security by evaluating your Email Security Score today and ensuring your domain is protected against email threats.

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