Why does DMARC fails? Learn how to improve your email performance

Do you know what makes the DMARC protocol fail? Many things can trigger this kind of failure, most of which are related to authentication issues.

Moreover, identifying the main cause of DMARC failures will be the most important step toward healthier email deliverability. 

Sometimes, that’s the reason why your Conversion Rate Optimization suffers, once emails are not successfully sent.

Because of that, we prepared this article to help you understand this authentication protocol, how to manage failures, and how to improve your email performance.

What is DMARC?

The protocol called Domain-based Message Authentication, Reporting & Conformance, as known as DMARC, uses the Sender Policy Framework (SPF Email), and Domain Keys Identified Mail method (DKIM), in order to check how authentic and legitimate an email sender is.

In addition, the DMARC protocols work side by side with ISPs (Internet Service Providers), once they have a common objective, which is reducing the circulation of dangerous messages on the web, such as spoofing, phishing, and spam.

The DMARC system basically determines how email senders should manage emails that didn’t receive authentication by SPF records, or DKIM. Actually, they have the options of senders that can:

• monitor strange sending IPs for further analysis;
• choose to send them straight to the junk folders;
• choose to block these domains definitely.

After the DMARC work is done, the ISPs can easily track spammers or malicious senders, avoiding receivers getting too many harmful messages.

Other than that, all these authentication services are efficient tools to keep away from email blacklists, which is essential when you need to make sure your domain is not at any risk. 

In conclusion, DMARC and ISP filters are necessary to protect the authenticity and transparency of email senders, minimizing cybercrimes and cases of false identities.  

Why does DMARC fails?

If emailing is an important channel of communication for your company, as it is in most cases, DMARC fails are a matter of deep concern.

First of all, when we have a problem, we should analyze what is causing it. We can resolve these failures if we understand their causes.

Even when emails are authenticated through the SPF and DKIM evaluation, the DMARC can still fail in the DMARC standards. Let’s understand how and why it happens.

DMARC: Alignment Failures 

The checking made by DMARC is quite simple. It verifies if the domain mentioned in the “FROM” visible header matches the domain mentioned in the hidden Return-Path header (SPF records), and the DKIM signature header (DKIM method).

That’s why the DMARC evaluation is known as “domain alignment”, once the email is only approved by DMARC if there is a match between the visible and hidden domains.

Domain misalignment is a possible cause for DMARC fails, which means the email originated at an unauthorized source, as SPF and DKIM don’t consider the “FROM” part of an email in their analysis.

DMARC: Alignment Mode

According to the nature of an analysis performed by DMARC for SPF and DKIM, there are two alignment modes:

• Strict Mode: when senders choose this option, the originating domain and the “FROM” header domain must be identical.
• Relaxed Mode: this method allows subdomains to be used to send emails because the DMARC is going to check only the top-level domains of an address, making sure they are the same.

The DMARC relaxed mode is more suitable when you use third-parties emails to send messages to your audience. You can choose either alignment mode, according to your necessity and needs.  

Set DKIM signature for your domain

When you don’t specify a signature for your domain, it can cause DMARC fails. That’s because the ISPs will set up a default signature for your domain, triggering misalignment issues, once the “FROM” header won’t be aligned with the original domain.

In case of many DMARC failures, try setting up a DKIM signature for your domain, making sure the alignment process is successful.

Email forwarding

Having problems with authentication is very common in email forwarding. When you create SPF records, for example, you can’t forget the third-party addresses.

Email authentication frequently fails in forwarding messages when the new sender is not included in such records.

In DKIM protocols, senders only have problems when they modify the content and/or structure of the original message. Otherwise, the email forwarding is not affected by DKIM.

As DMARC requires only one approval, either by SPF or DKIM, it’s recommendable to use both on all legitimate sending sources, making sure forwarded messages are successfully sent.  

Domain spoofing

When all your protocols for authentication are set up and functioning, but you are still facing problems regarding DMARC fails, your domain might be spoofed or forged.

That means that bad-intentioned people are sending harmful emails that appear to be coming from your domain, through a malicious IP address. In this case, you should be aware of the DMARC policies:

• Monitor (p=none): unqualified emails can be sent to users mailboxes;
• Quarantine (p=quarantine): unqualified emails are sent to junk or spam folders;
• Reject (p=reject): unqualified emails are permanently blocked.

The Reject Policy will prevent harmful emails from reaching your subscribers, in case your domain is spoofed, making sure they don’t get in touch with these dangerous IP addresses. 

Improve your email performance

Understanding how the DMARC protocol works is important to improve your email performance, as it protects your sender score, taking care of your legitimacy and authenticity.

Let’s analyze how you can explore this method, to make the most of its features, including improving your security, visibility, identity, and delivery.

Monitor your domain with DMARC

DMARC monitoring is the practice of reviewing DMARC reports and looking for unauthorized senders using your domain for dubious purposes, such as spoofing or spamming.

When you set up your first DMARC record, you can include an email address to receive further reports. When a change in your sending methods happens, you can keep track of them, verifying both the status of approved sources and new sending services.

This way, you can protect not only your deliverability but your recipients integrity as well. 

Gather all the IP addresses and domains to authenticate them with SPF and DKIM

In order to explore the DMARC benefits, all your sending methods must be authenticated through SPF and DKIM records. Don’t forget to include third-party sources as well.

Learn how to create an SPF record to improve your results.

Authenticate all your legitimate servers and reach DMARC Alignment and Compliance

Keeping an eye on DMARC reports will help you monitor all the activity that originated in your legitimate servers, including the volume of messages delivered through SMTP servers.

This makes you identify when a sender is adopting uncommon volume patterns or when you don’t recognize a sender at all. In both cases, action is required.

Authenticating legitimate servers and agreeing to DMARC alignment and compliance policies is important to have a good reputation as a sender. Later on, this process can help you if you want to authenticate your messages through BIMI.

Enforce your DMARC Policy

In case of the absence of SPF or DKIM protocols, the automatic DMARC will fail. So, setting up these protocols should be the first thing to do.

After that, email senders can determine what is to be done when a certain email is non-compliant (as mentioned earlier, they have three options – Monitoring, Quarantine, and Reject).

You can start by monitoring your sources, which is going to give you insight into how your domain is being used. After some weeks, you can activate the Reject Mode, eliminating any improper use of your domains.

Enforcing the DMARC Policy is an effective way to prevent your messages from going to spam.

Now that you have the answer of why does DMARC fails, learn more about the best practices for having a sucessfull email marketing. Check SafetyMails’ content about the strategies to build a subscriber list.

What the postmasters of the main email providers say about using DMARC

Google

Google’s postmaster policy recommends always configuring DMARC authentication for your domain. You can define a DMARC policy with minimal application, using the “none” policy (p=none) and applying it to 0% of your messages (pct=0)1. This allows you to start receiving reports without the risk of your messages being rejected or sent to the spam folder by the receiving servers2.

In addition, only a small percentage of messages are affected, and recipients can review the messages that are sent to the spam folder3. Therefore, by implementing DMARC, you strengthen the security and reliability of email communications, protecting users and the brand from fraud and abuse

Outlook

Outlook also respects the DMARC policy. If an email fails DMARC validation and the sender policy is set to “p=reject”, Outlook will reject the email1. The DMARC policy specifies what to do with messages that fail DMARC validation (reject, quarantine or no instruction)2.

Therefore, by implementing DMARC, Outlook helps protect the reputation and brand of senders against spoofing and prevents recipients from receiving emails from unverified senders.

Yahoo

Yahoo has also adopted a strict DMARC policy to reinforce email security and protect its users. Yahoo’s policy requires senders to authenticate their emails using SPF and DKIM, as well as imposing strict alignment checks to prevent spoofing and phishing attempts1.

Therefore, by implementing DMARC, Yahoo helps protect senders’ reputations and brands from threats and ensures that emails are delivered securely.