DMARC: What is it and How does it Work?

Email authentication is foundational in maintaining trust and security in digital communications. It serves as a crucial line of defense against phishing, email spoofing, and other cyber threats that exploit the trust users place in email communications. 

Email fraud and phishing pose significant challenges in the way of business email communications. Cybercriminals utilize sophisticated techniques to craft deceptive emails that appear genuine, luring recipients into revealing sensitive information, such as login credentials, financial data, or personal details. This highlights the need for email authentication techniques like DMARC. 

What is DMARC in Email?

DMARC is an email authentication protocol that allows email domain owners to specify which mechanisms they use to authenticate their email messages and how mail servers receiving messages from their domain should handle authentication failures.

DMARC is intended to help combat email fraud and phishing attacks by allowing email recipients to determine whether or not an email message claiming to come from a specific domain is actually from that domain. It functions by allowing domain owners to publish policies that instruct receiving email servers on how to handle messages that fail authentication checks.

DMARC Full Form

DMARC stands for “Domain-based Message Authentication, Reporting, and Conformance”.

Here’s a breakdown of the various components of “DMARC” acronym:

Domain-based: DMARC runs at the domain level, allowing domain owners to specify policies for email authentication and processing.

Message Authentication: DMARC allows domain owners to designate the authentication procedures used to validate incoming email messages, such as SPF (Sender Policy Framework) and DKIM (DomainKeys Identified Mail).

Reporting: DMARC creates thorough reports that provide insights into email authentication outcomes, including successful and failed authentication efforts, as well as information about the messages’ sources.

Conformance: Domain owners can use DMARC to describe the actions that receiving mail servers should do when an email fails authentication tests, ensuring that the established policies are followed.

How does DMARC Work?

A message is sent from an authorized server to the DMARC-compliant domain’s SPF record and/or DKIM signature, which are stored at the DNS level. 

If either check passes, the message is termed as “DMARC PASS”; if both fail, the message fails DMARC (since it didn’t meet SPF or DKIM requirements).

Depending on the DMARC policy configured, the message can now be rejected or discarded, flagged as spam or quarantined, or delivered as is. 

Once you’ve set up DMARC correctly for your domain, you can enable DMARC reports. This helps you identify suspicious messages so you can take action against them quickly—and keep your subscribers safe!

Why is DMARC Important?

• DMARC ensures Email Authentication

DMARC is a powerful email authentication protocol that helps protect domains from email fraud and abuse.

• DMARC protects from Domain Spoofing

DMARC is an essential tool in protecting domains from spoofing attacks, which are a type of email-based fraud in which an attacker sends emails that appear to come from a trusted domain.

• DMARC protects against phishing attacks

DMARC is a powerful tool in the fight against phishing attacks, which are a type of email-based scam that attempts to trick users into divulging sensitive information or performing malicious actions. 

Benefits of DMARC

DMARC benefits a company/ business by putting in place an authentication mechanism that gives domain owners the power to not only set policies for emails that fail authentication, but also report back to the sender regarding those failures.

Here are some of the benefits of implementing DMARC:

1. Email Fraud Prevention: You can prevent phishing attacks by using DMARC to identify spoofed emails and prevent them from being delivered to user inboxes.
2. Improves Brand Reputation: You can improve your brand reputation by ensuring that only legitimate messages are delivered to recipients’ inboxes.
3. Minimizes Spam: You can reduce the amount of spam in your customer’s inboxes by preventing fraudulent messages from reaching them in the first place.
4. Provides Visibility: Quickly identify who is sending emails on your behalf without your knowledge using DMARC reports.
5. Improves Deliverability: You can improve your email’s deliverability rate by 10% over time by deploying the protocol correctly for your emails.

How to Set Up and Enable DMARC?

Setting up DMARC can be a bit technical and we have covered it in detail in our DMARC setup guide. Here are the general steps involved: 

1. Assess your email-sending infrastructure

Before setting up DMARC, you need to have a good understanding of your email-sending infrastructure. This includes identifying all the email servers and third-party services that send emails on your behalf, such as marketing automation platforms, customer service tools, and email delivery services.

2. Create a DMARC policy

A DMARC policy tells email receivers how to handle messages that fail DMARC checks. You need to create a DMARC policy for each domain you want to protect. The policy will include the following elements:

• Policy mode: You can choose between two policy modes – “none” and “quarantine” or “reject”. “None” means that the receiver will continue to accept and deliver messages that fail DMARC checks. “Quarantine” or “reject” means that the receiver will send those messages to the spam or junk folder, or even reject them outright.
• Alignment requirements: You can specify the alignment requirements for your domain’s SPF and DKIM records. This means that the domain name in the “From” header of an email must match the domain name in the SPF and/or DKIM record.
• Reporting: You can configure DMARC to send reports to your email address or a third-party service. These reports will provide information on DMARC activity, including the number of emails sent, the number of emails that passed DMARC checks, and the number of emails that failed DMARC

3. Create and Publish a DMARC TXT record

You can sign-up with PowerDMARC for free to create your DMARC record using our DMARC record generator tool. Following this, you need to access your DNS management console to publish your record or take the help of your DNS hosting provider to publish it on your behalf.

What does DMARC Look Like?

The structure of a DMARC record is defined in the DNS (Domain Name System) as a TXT record associated with the domain. It contains several tags that specify the DMARC policy and reporting options. Here’s an example of what a DMARC record might look like:

_dmarc.example.com.     IN TXT    “v=DMARC1; p=reject; rua=mailto:[email protected]; ruf=mailto:[email protected]; sp=reject”

In this example:

• “_dmarc.example.com.” refers to the specific domain where the DMARC record is being set up. In this case, it is “example.com.”
• “IN TXT” indicates the record type as a text record.
• “v=DMARC1” signifies that the version of DMARC being used is DMARC version 1.
• “p=reject” sets the DMARC policy to “reject,” which instructs receiving email servers to reject or discard emails that fail DMARC authentication checks.
• “rua=mailto:[email protected]” specifies the email address “[email protected]” as the destination to receive aggregate DMARC reports, which provide information about email authentication results.
• “ruf=mailto:[email protected]” designates the email address “[email protected]” as the destination to receive forensic DMARC reports, which provide detailed information about individual failed email authentication events.
• “sp=reject” sets the subdomain policy to “reject,” ensuring that the DMARC policy applies to subdomains as well.

DMARC, SPF and DKIM – Pillars of Email Authentication

SPF (Sender Policy Framework) is an authentication protocol that defines which mail servers are authorized to send emails on behalf of a specific domain. By creating SPF records in the domain’s DNS, the owner specifies the allowed IP addresses or domains that are permitted to send emails using that domain.

DKIM is an email authentication protocol that allows the sender of an email to digitally sign the message with an encrypted signature, which is associated with the sender’s domain. The receiving email server can then verify the authenticity of the message by checking the DKIM signature against the corresponding public key in the sender’s DNS records. 

Combining DMARC, SPF and DKIM Against Email Fraud

When it comes to email authentication, implementing DMARC, SPF, and DKIM together provides a robust defense against email spoofing and phishing attacks. Let’s explore the benefits of using these authentication methods in combination:

Comprehensive Protection: The combination of DMARC, SPF, and DKIM provides a layered approach to email authentication, offering comprehensive protection against email spoofing, phishing, and unauthorized senders.

Enhanced Email Deliverability: By ensuring that emails are properly authenticated and aligned with domain policies, the chances of legitimate emails being marked as spam or rejected are significantly reduced.

Brand Reputation Protection: Implementing these authentication methods helps maintain the integrity of your brand by preventing email abuse and spoofing, safeguarding your reputation among recipients and email service providers.

Improved Security: The use of DMARC, SPF, and DKIM together minimizes the risk of unauthorized entities sending malicious emails on behalf of your domain, strengthening overall security and mitigating potential cyber threats.

Reporting and Visibility: DMARC provides valuable reporting insights into email authentication failures, allowing domain owners to identify and address issues promptly, enhancing the effectiveness of their email security measures.

DMARC and SPF

DMARC and SPF is a powerful duo to bolster email security and protect against email spoofing and phishing attacks. DMARC builds upon SPF’s sender validation capabilities by allowing domain owners to set a policy on how to handle messages that fail SPF checks.

Should you use SPF and DKIM if you already have DMARC?

Yes, it is highly recommended to use both SPF and DKIM even if you have already implemented DMARC. DMARC is designed to work alongside SPF and DKIM, and together they form a powerful email authentication framework.

DMARC FAQ

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Ahona Rudra

Digital Marketing & Content Writer Manager at PowerDMARC

Ahona works as a Digital Marketing and Content Writer Manager at PowerDMARC. She is a passionate writer, blogger, and marketing specialist in cybersecurity and information technology.

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