So, you have finally set up DMARC to protect your domain from phishing and spoofing attacks and improve deliverability. Does that mean your job is done, and you don’t have to worry about anything anymore? Well, in theory, it should all work just fine, but that’s not always the case!
When you implement DMARC, one of the major problems that you might encounter is DMARC failure. This happens when your outgoing emails don’t pass the necessary checks; that is, SPF and/or DKIM fails, triggering DMARC to mark them as unverified. This means your critical emails may never reach customers, partners, or teammates. Worse, if your domain is not completely secured, someone else may continue to spoof it and send fake emails that look like they are from you.
But remember, DMARC failure doesn’t necessarily mean that something is broken; it just means that something is misaligned.
In this article, we will take a look at why this happens and what you can do to fix it.
What is the Reason Behind DMARC Failure?
Implementing DMARC is confusing. You set it up thinking it’ll just work, but suddenly you’re seeing “DMARC failure” pop up in reports. Why does this even happen?
The Domains Don’t Match (DMARC Alignment Failure)
DMARC wants to make sure the email is really coming from you. To do that, it checks if the domain in the “From” address (what people see in their inbox) matches the domain used in two hidden parts of the email: the Return-Path (for SPF) and the DKIM signature. If at least one of those matches the “From” address, your email is considered safe. But if neither matches, DMARC says the email is unauthorized—even if it’s a genuine email you sent.
This usually happens when you use other services to send emails for you—like email marketing tools, customer support platforms, or CRMs—and they haven’t been properly set up to send on your behalf.
DKIM isn’t Properly Set Up
Improper DKIM implementation is another reason why DMARC might fail for your domain.
If you don’t properly publish your DKIM record in your domain’s DNS, your email service provider will apply a default DKIM signature to that email. What this means is that the default signature won’t likely match the “From” domain, causing the DKIM check—and in turn, the DMARC check—to fail.
You Didn’t List All Your Senders
Another common reason why DMARC fails is that not all of your email-sending sources are included in your DNS settings—specifically, in your SPF record. When you’re implementing SPF, you’re basically telling the receiving mail servers: “These are the only servers that are permitted to send emails from my domain.” So, if you’re using third-party platforms, you need to include them explicitly. But if you fail to do so, SPF fails for emails sent from those services. And unless DKIM is correctly set up and aligned, DMARC will fail, too.
Your Email Went Through an Intermediary Server
When you forward an email, it passes through an intermediary server, which might make small changes to the email— like adding a footer or a disclaimer. The changes might seem insignificant to you, but to the receiving server, they are major red flags and can break the DKIM signature. With both SPF and DKIM failing, DMARC has no valid authentication path to trust, which is why it fails.
How to Fix DMARC Failure Error?
So, we know what causes DMARC to fail, but what can you do to fix the problem and ensure that your emails get delivered safely and seamlessly?
Here are a few strategies that you should follow to get things back on track:
Start With the “none” Policy
If you’re just starting out, don’t jump straight to blocking emails. Set your DMARC policy to p=none. This doesn’t block anything—it just helps you watch and learn. With this policy, you will get reports that show who is sending emails using your domain, which ones are passing, and which ones are failing. That way, you can spot problems without breaking anything. Once you understand the traffic and things are in place, you can slowly move to quarantine (put suspicious emails in spam) or reject (block them).
Check if SPF and DKIM are Properly Set Up
For an email to pass DMARC, it must pass at least one of the checks— either SPF or DKIM. If both fail, DMARC will definitely fail, too.
Begin by ensuring your SPF record includes all services that send emails on behalf of your domain—such as Gmail, Mailchimp, Zoho, or any other tool you’re using. If something’s not included, emails from that tool will not pass SPF.
Next up, check your DKIM configuration. DKIM is a digital signature for your emails. It verifies that the email actually came from you and wasn’t altered during transit. But it will only work if the domain in the DKIM signature is the same as your “From” address.
Although you only need just one— either SPF or DKIM for DMARC to pass, if you have both of them aligned, your set up will be stronger and more reliable.
Check your DMARC Reports Regularly
Once you start receiving DMARC reports, make sure you pay close attention to them. These reports tell you what’s working and what’s not. You can see if someone’s trying to spoof your domain or if a tool you’re using isn’t set up properly.
If something starts failing, these reports will help you detect it early—before emails get lost or your reputation takes a hit.
