What is DMARC – All You Need to Know About the Most Effective Email Authentication Protocol

With people increasingly using emails for communication, malicious actors have more excellent opportunities to commit cybercrimes. Businesses should use email authentication protocols like SPF, DKIM, and DMARC as critical components of their cybersecurity strategy.

The internet has made it convenient for everyone to communicate using emails, and emails are the primary communication mode for most businesses. Rarely does an hour pass by without people working in organizations checking their official email accounts.

Unfortunately, while emails have increased the convenience levels, they have also provided more opportunities for malicious actors to transmit malware and try out other network infiltration activities to steal data and cause financial and reputational losses. While there are various ways to prevent falling prey to phishing attacks, using email authentication protocols like DMARC, SPF, and DKIM can help nip the problem in the bud. This article discusses DMARC in detail.

Some Eye-Opening Statistics on Email-related Threats

Here are some alarming statistics showing how grave the situation of email-borne cyberattacks like phishing and spoofing is.

What is DMARC?

So, what is DMARC, and what does DMARC stand for? DMARC is the abbreviation for ‘Domain-Based Message Authentication Reporting and Conformance’. DMARC is an email authentication and security protocol that protects a business organization’s email domain from being misused by malicious actors for phishing scams, email spoofing, and other cybercrimes. While working in conjunction with existing email authentication techniques, Sender Policy Framework (SPF) and DomainKeys Identified Mail (DKIM), DMARC makes it more secure by adding a critical function, namely reporting.

DMARC is useful to protect your email domains against cyber threats like phishing or spoofing. Publishing a DMARC record into the DNS provides the domain owner insight into who sends email on their domain’s behalf. As it allows for detailed information about the email channel, the domain holder has complete control over the domain. Thus, you can ensure that your customers and email recipients receive emails sent on your behalf without fail. Besides, it confirms the authenticity of the email source sent from the domain. It also prevents others from sending any email using your name.

DMARC – A Brief History

Having understood the DMARC definition, here is brief background information on how DMARC originated and gradually developed into an internationally accepted email authentication standard.

The DMARC standard was initially introduced in 2012 to prevent email abuse. PayPal joined Google, Microsoft, and Yahoo to create DMARC using existing email authentication protocols like SPF and DKIM. DMARC was initially conceived as an email security protocol and adopted by security experts in the financial industry.

Since its introduction, other industrial sectors have also gradually accepted that DMARC is an email authentication standard. In addition, email marketers consider DMARC a critical aspect of online security because it improves deliverability. Today, almost all the major ISPs support DMARC, and it is awaiting approval as an open standard protocol from IETF (Internet Engineering Task Force).

Why is DMARC Required?

Statista reports the existence of more than four billion email users globally. This figure is increasing and could reach 4.6 billion by 2025. While email provides convenience, it has also made it easier for threat actors to perpetrate their malicious deeds. DMARC is necessary to prevent these malicious actors from using the email channel to introduce malware and carry out phishing scams.

Besides providing a complete insight into email channels, DMARC makes it easy for users to identify spoofing attempts and phishing attacks. This email authentication protocol can reduce phishing attacks, prevent malware and spoofing, and protect against BEC, brand abuse, and other email-based cyberattacks.

Here are some more statistics to support DMARC deployment.

  • FBI Internet Crime 2020 report states that Business Email Compromise (BEC) attacks caused losses worth $1.8 billion in 2020. The report also highlights email as the primary channel for spreading ransomware. In addition, phishing incidents have increased by 110%.
  • CISCO 2021 report indicates that 80% of the global email traffic is spam.
  • Verizon 2020 Report points out social engineering attacks as the prime cause of 22% of data breaches.  
  • The Europol 2019 Report identifies that phishing is involved in 78% of cyberespionage incidents.
  • The Sonic Wall Report 2021 highlights that Microsoft Office files comprised 67% of malicious files used in email phishing scams in 2020.

How Can DMARC Help?

Adversaries send phishing emails by impersonating genuine domains. The target acts on the email message, assuming it originated from an authentic source. In the process, the network systems of business organizations get compromised. DMARC can help because it enables domains to gain insight into their email channels. Thus, business organizations find it helpful to deploy and enforce a robust authentication policy.

When domain owners enforce the DMARC policy ‘p=reject,’ organizations get protection against the following cybercrimes.

  • Phishing attempts on the organization’s customers
  • Ransomware and other malware attacks
  • BEC, spear phishing, and CEO frauds

Usually, organizations try to gain insights into their email channels after a threat actor has made a phishing attempt. However, DMARC protection ensures these business entities and domain owners complete insight into their email channels much earlier. Thus, it enables organizations to alert their customers well in advance about the possibilities of spoofing, phishing, or other cyberattacks.

How Does DMARC Work?

One of the classic examples of a phishing scam is in the banking sector. Malicious actors spoof banking website domains and send emails on the bank’s behalf to customers stating that their card/account has been deactivated. It asks the customer to revalidate specific personal details to activate the account. Customers get fooled into thinking it is a genuine email and act on it accordingly in full faith. As they click on the website link provided in the email, they reach a fraudulent website resembling their bank’s landing page. Subsequently, the customers log in to their internet banking accounts using their credentials and allow the threat actors to steal their personal information.

To protect internet domains from such scams, users used email authentication techniques like SPF and DKIM earlier. However, the perpetrators have become more sophisticated enough to bypass these security measures comfortably. In such a circumstance, DMARC can protect customers by creating a link between SPF and DKIM. Publishing DMARC in your DNS record lets you gain insight into your email channel. For example, DMARC generates RUA (Aggregate), and RUF (Forensic) reports daily. These reports are sent to your registered email address published in your DMARC record.

RUA DMARC reports have the following characteristics.

  • They are sent daily and provide a complete overview of all email traffic.
  • This report offers a comprehensive list of all IP addresses that have attempted to transmit email messages to a receiver using your domain credentials.

RUF DMARC reports are different from RUA reports in the following manner.

  • These reports are sent on a real-time basis and for failures alone.  
  • They mention the original message headers and may include the original message.

DMARC service providers offer a user-friendly dashboard for monitoring and analyzing your, DKIM, SPF, and DMARC reports. DMARC works on three DMARC policies to enable you to decide what happens to your emails.

  • The ‘None‘ Policy collects data and monitors your current email channel.
  • The ‘Quarantine‘ Policy delivers malicious emails into the receiver’s spam or junk email folder.
  • The ‘Reject‘ Policy ensures that the email is not delivered to the receiver.

In this way, DMARC secures your domain and gives you the discretion to decide the course of action it should take when the ISP servers receive malicious emails. DMARC is a powerful tool to help secure your email domain if used correctly. It needs proper configuration because a ‘Quarantine’ or ‘Reject’ policy can lead to many false positives. Therefore, it is better to check up with your DMARC service provider about the correct setup to secure your email channel.

The Spoofing Example

The above sections showed how DMARC works to secure your emails. It instructs email receivers what action to take on incoming emails, especially those that fail DMARC checks. At the outset, the email receivers verify whether the incoming messages possess valid SPF records and DKIM records and have proper SPF and DKIM alignment with the sending domain. Then, it helps check whether the messages are DMARC-compliant or DMARC-failed. The defined DMARC policy takes over upon verifying the authentication status to handle the email accordingly.

Three DMARC policies have been discussed above already. The simple example presented below shows what they signify and how they help DMARC mitigate the impact of spoofing.

  1. Monitoring Policy: p=none
    The ‘p=none’ monitoring policy gives insight into the email channel by instructing the email receivers to send the respective DMARC reports to the address published in the DMARC Record. However, it does not recommend the email receivers treat these messages differently even if they fail DMARC checks. Therefore, this policy does not affect the deliverability of the email. In other words, the policy results in delivering all messages, whether genuine or not.

  2. Quarantine Policy: p=quarantine
    The Quarantine policy is definitive because it instructs the email receivers on how to act if the email message fails or passes DMARC checks. If the message passes DMARC checks, this policy asks the receivers to deliver the emails into the primary inbox of the receiver. On the other hand, if the message fails DMARC checks, it specifies that it should get forwarded to the receiver’s spam folder. As a result, the quarantine policy mitigates the spoofing impact but delivers it to the spam folder. If required, the receiver can open the email from the spam folder or delete it. Thus, it partially affects the email’s deliverability as the message is treated as spam.

  3. Reject Policy: p=reject
    The Reject policy is authoritative because it provides clear instructions to email receivers to reject all emails that fail DMARC checks. As a result, the receiver’s inbox receives only those emails passing the DMARC authentication check. The DMARC failed emails do not land in the receiver’s inbox. Besides, it ensures deletion of these incorrectly set up emails (also referred to as spoofing emails) to mitigate spoofing entirely. Unlike the previous policy, you cannot find such emails even in the spam folder.

Overriding DMARC: An Important Point to Note

One should note that a DMARC record instructs handling emails according to the DMARC policy. However, email receivers are not obligated to follow the DMARC policy strictly. Instead, they can use their policy and decide accordingly. For instance, suppose the email receiver judges the email as legitimate. In that case, they can apply their local policy and deliver the message to the receiver’s inbox even if it fails DMARC checks. In addition, the email receiver’s local policies can be set to override the DMARC ‘p=reject’ policy.

DMARC – Common Misunderstandings

By now, it must be clear what is a DMARC policy, what DMARC stands for, and how DMARC works. Organizations can mitigate spoofing and phishing attacks, block malware, and increase email deliverability using DMARC records. However, while it is a powerful tool, DMARC has caused certain misunderstandings. Below is an examination of a few of the most common misconceptions and their clarification.

Misunderstanding 1: DMARC is a quick-fix solution.

Contrary to what many people believe, DMARC does not guarantee the complete security of your email channel. It certainly improves email deliverability, but email servers can formulate their local policies and allow them to override DMARC policies. However, internet service providers adopting DMARC policies are more likely to ensure that your emails land in the receiver’s primary inbox. Thus, even when DMARC provides many benefits, placing and enforcing a DMARC record is not a quick-fix solution for email deliverability.

Misunderstanding 2: Immediately enforcing a ‘p=reject’ policy is the right solution.

Generally, organizations follow a knee-jerk reaction on encountering a phishing attack on their behalf. They lock down their email channel by placing a DMARC record and immediately enforcing a 100% ‘p=reject’ policy. While it seems to be an effective way to block phishing attacks instantly, it has its downsides. Some of your legitimate emails can also get lost under such circumstances.

DMARC analyzing service providers have noted that organizations never have a 100% compliance rate in most cases when they start with DMARC. Therefore, the consensus is that organizations should initially begin with a ‘p=none’ policy and monitor each email through the reports submitted by DMARC. It helps improve SPF and DKIM authentication. This process can take one month to a year, depending on the organizational email environment.

Subsequently, the organization can go for a ‘p=reject’ policy. Applying the p=quarantine’ rule is even better before going for the ‘reject’ policy if you are patient enough and ready to wait some more time. In that case, the messages marked as failed will not get directly rejected. The system will move them to a different section where you can still verify them and take them back if they are falsely marked failed. Immediately enforcing the ‘p=reject’ policy is not a sound decision.

Misunderstanding 3: DMARC protects all inbound email streams.

Though DMARC primarily works on the outbound email channel component, it does not necessarily mean that all inbound stream is unaffected. The effect can spill over, with DMARC influencing a small part of the inbound email channel. For example, emails sent to colleagues are affected by DMARC. These emails are outbound emails for the server, but they remain inbound for the network. Therefore, DMARC does influence these emails.

Benefits of an Effective DMARC Policy

Having an effective DMARC policy setup is beneficial to organizations in many ways, as listed below.

  • It helps mitigate email-based cyber threats and gives a complete insight into the email channels. In addition, an effective DMARC policy provides perfect security and disallows malicious actors’ unauthorized use of your email domain.
  • It provides organizations with enhanced visibility of who and what is using your email domain to send emails across the internet.
  • It improves email deliverability and, thus, enhances organizational reputation.
  • It improves your identity across a massively growing footprint of DMARC-capable receivers.
  • By uplifting the organization’s reputation, it provides the customer with an enhanced user experience.

Traits to Look Out For in a DMARC Analyzing Software Solution

ISPs and domain service providers should have an effective DMARC policy to prevent spamming directed to your customers and cyberattacks originating through emails employing spoofing and phishing. Here are the traits one should look for in a DMARC analyzing software solution.

  • The platform should be user-friendly and guide you perfectly towards a ‘p=reject’ policy in the quickest manner possible without bypassing or ignoring any email authentication standard.
  • It should provide an effective SaaS solution that empowers organizations to manage complex DMARC deployment comfortably.
  • The solution should provide 360-degree visibility and governance across all email channels.
  • The entire DMARC implementation and usage procedure should be as easy as possible.

Final Words

The internet has become an integral constituent of human life, and email correspondence has increased manifold. While convenient, it opens up opportunities for malicious actors to have a free hand at email spoofing directed at unsuspecting targets intending to infiltrate information systems and cause reputational and financial loss to the organization. Email channels are the most vulnerable in any network system.

Therefore, organizations and domain service providers should ensure protection from phishing attacks to reduce cybercrime incidents significantly. Email authentication protocols like SPF, DKIM, and DMARC can prove handy in such circumstances. The information on DMARC provided in this article in detail will help all organizations to deploy the solution quickly to combat email-based cyber threats.

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DMARC Report is designed for large scale reporting needs, with a combination of domains and message volume.