Setting up a DMARC record is a fantastic first step towards securing your email domain. It tells the world you're serious about protecting your brand from phishing and spoofing. But creating a DMARC record with a policy of 'none' is just the beginning of the journey. The real security benefits come when you confidently move to a policy of 'quarantine' or, even better, 'reject'. This is where many people get stuck, worried that they might accidentally block their own legitimate emails.
That fear is understandable, but it doesn't have to be a blocker. Transitioning your DMARC policy is a process that, when done carefully and methodically, can be perfectly safe. It’s not about flipping a switch overnight; it's about a gradual, data-driven approach. In this guide, I'll walk you through the exact steps to safely transition your DMARC policy from a passive monitoring state to a powerful enforcement policy, ensuring your legitimate mail keeps flowing while illegitimate mail gets stopped.
Before we dive into the transition process, let's quickly review what the different DMARC policies actually do. A DMARC policy instructs receiving mail servers on how to handle emails that claim to be from your domain but fail SPF and/or DKIM authentication checks.
p=none (Monitoring)
v=DMARC1; p=none; rua=mailto:reports@yourdomain.com;p=quarantine (Spam Folder)
v=DMARC1; p=quarantine; rua=mailto:reports@yourdomain.com;p=reject (Block)
v=DMARC1; p=reject; rua=mailto:reports@yourdomain.com;Policy Breakdown
The entire process relies on starting with p=none. This phase is all about gathering data. By including a rua tag in your record, you'll start receiving aggregate reports. These reports are XML files that detail which servers are sending email on behalf of your domain and whether those emails are passing or failing authentication checks. This information is the bedrock of your transition plan.
Your first DMARC record should always start with a monitoring policy. This allows you to collect data without any risk to your email delivery. The goal here is to get a complete picture of your entire email ecosystem. You need to identify every single service and server that sends email for your domain, from your primary mail provider like Google Workspace or Microsoft 365 to third-party services like marketing platforms, CRMs, and customer support tools.
You should let this monitoring phase run for at least a couple of weeks, but often longer. The duration isn't about a set number of days; it's about reaching a point where you are no longer discovering new, legitimate sending sources in your DMARC reports. For businesses with complex email setups, this could take a month or more. During this time, your job is to analyze the reports and ensure every legitimate source is properly configured with SPF and/or DKIM so that it passes DMARC.
Once your DMARC reports show that nearly all of your legitimate mail is passing DMARC checks, and you understand the source of any remaining failures, you're ready to consider moving to the next phase. Don't rush this; moving on too early is the most common mistake people make.
Now that you're confident in your analysis, it's time to dip your toes in the water of enforcement. Instead of jumping straight to a full quarantine policy, we'll use a powerful but often overlooked tool: the percentage tag (pct). This tag lets you apply your policy to only a small percentage of failing emails, giving you a safe way to test the waters.
DMARC Record with p=quarantine and pct=5
dns
v=DMARC1; p=quarantine; pct=5; rua=mailto:reports@yourdomain.com;This record tells receivers to apply the quarantine policy to just 5% of emails that fail DMARC. The other 95% will be treated as if the policy was p=none.
By starting with a low percentage, you can monitor your reports and ensure no legitimate mail is being unexpectedly sent to spam. It's a safety net. If you see any problems, you can quickly revert the change or fix the underlying authentication issue for that sending source without having caused a major delivery problem. As you gain confidence, you can gradually increase your DMARC record percentage.
Once you've been running at a full quarantine policy for a while with no issues, you can prepare for the final step: moving to p=reject. The difference between quarantine and reject is significant; a quarantine policy might allow a malicious email into a spam folder, but a reject policy stops it from being delivered at all. This is the ultimate goal for domain security.
Just like the move to quarantine, the switch to reject should be done gradually using the percentage tag. You can follow the exact same incremental process you used before. Start with p=reject; pct=5, monitor your reports, and slowly work your way up to 100%. This methodical approach minimizes risk and gives you multiple opportunities to catch any potential problems before they have a widespread impact.
Impact
Security level
Impact
Security level
Transitioning your DMARC policy is a marathon, not a sprint. By following this phased approach, moving from monitoring to quarantining and finally to rejecting, you can significantly bolster your email security without disrupting your business operations. Each step is built on the data and confidence gained in the previous one.
Remember, DMARC isn't a 'set and forget' protocol. Even after you reach p=reject, you should continue to monitor your reports. New sending services may be added over time, and you'll need to ensure they are properly authenticated. Staying vigilant is the key to maintaining long-term domain security.
How long should I stay at p=none?
What if I see legitimate emails being quarantined?
Can I have different policies for my main domain and subdomains?
Is it mandatory to move to p=reject?
Matthew Whittaker
6 Jul 2025
Discover the essential benefits of implementing DMARC for your email. This article explains how DMARC enhances your security by preventing domain spoofing and phishing, boosts deliverability by improving your sender reputation, and provides invaluable visibility into your email ecosystem. Learn why DMARC is a non-negotiable tool for protecting your brand and ensuring your messages reach the inbox.
Michael Ko
9 Jul 2025
Learn how to find, vet, and hire a DMARC professional to secure your email and improve deliverability. This guide covers what to look for in an expert, where to find them, and the key questions to ask to ensure you're protecting your brand from phishing and spoofing.
Michael Ko
10 Jul 2025
Getting a 'DMARC verification failed' error? This post breaks down what it means, the common causes like alignment issues with SPF and DKIM, and how to fix it. Learn how to diagnose problems using DMARC reports and a step-by-step approach to secure your domain without blocking legitimate emails.
Matthew Whittaker
11 Jul 2025
Seeing a 'DMARC policy not enabled' warning can be confusing. This message doesn't mean something is broken, but rather that your DMARC policy is set to a monitoring-only mode (p=none) and not yet enforcing protection. This guide explains what the warning means, why starting with p=none is a critical first step, and how to methodically analyze your email sources to safely transition to an enforcement policy like p=quarantine or p=reject, ultimately securing your domain and improving deliverability.
Michael Ko
11 Jul 2025
Getting started with DMARC doesn't have to be complicated. This guide explains why a `p=none` policy is the safest first step, providing simple, copy-paste examples to help you start monitoring your email domain. Learn how to gain crucial visibility into who is sending email on your behalf without any risk to your deliverability.
Matthew Whittaker
11 Jul 2025
Ever felt lost in the alphabet soup of email security? This guide breaks down DMARC, SPF, and DKIM into simple concepts. We'll explain how SPF creates a guest list for your emails, DKIM adds a tamper-proof seal, and DMARC acts as the security chief, telling mail servers how to handle unverified messages, ensuring your emails are trusted and secure.
