Skip to the main content.
Talk to sales Start for free
Talk to sales Start for free

2 min read

What is DMARC?

What is DMARC?

Email security is a critical concern for organizations and they need measures to protect their email systems. DMARC, which stands for Domain-based Message Authentication, Reporting, and Conformance is a technical standard that helps safeguard email senders and recipients from advanced threats that can lead to data breaches. 


Understanding DMARC

DMARC is designed to address the vulnerabilities associated with email authentication. It enables domain owners to outline their authentication practices and specify the actions to be taken when an email fails authentication. DMARC adds an extra layer of protection to business email systems. It helps combat attacks like impersonation fraud, where attackers use a legitimate domain to send fraudulent messages. With DMARC, both senders and recipients can have greater confidence in the authenticity and integrity of their email communications.

Read more: What is an impersonation attack?


Defending against spoofing with DMARC

One of the primary threats that DMARC helps mitigate is domain spoofing. Cybercriminals often send fraudulent emails from legitimate domains to trick users into divulging sensitive information or making financial transactions. DMARC email security protocols play a significant role in preventing this type of attack. They allow senders to notify recipients that their messages are protected by SPF (Sender Policy Framework) and/or DKIM (DomainKeys Identified Mail) authentication. 

Additionally, DMARC provides instructions on handling emails that fail these authentication methods, minimizing the recipient's exposure to potentially fraudulent emails and protecting the sender's domain from exploitation.

Read also: Domain spoofing: How it works and what you can do to avoid it 


Understanding DMARC policies

DMARC policies determine how receiving mail servers process emails that they receive. There are three main policies available:


None (monitoring only)

This policy instructs email-receiving systems to send DMARC reports to the designated address without affecting email deliverability. It allows organizations to gain insights into their email channel and identify potential issues with authentication.



This policy instructs email-receiving systems to deliver non-compliant emails to the spam folder. It provides an intermediate level of protection by mitigating the impact of spoofing and reducing the chances of users interacting with potentially malicious emails.



The reject policy is the most stringent option. It instructs email-receiving systems to reject all non-compliant messages outright. Only emails that pass DMARC authentication will be delivered to the recipient's inbox. This policy significantly reduces the risk of spoofing and ensures that only legitimate messages reach the intended recipients.


Benefits of DMARC email security

Implementing DMARC email security offers several advantages for organizations:


Prevention of phishing and spoofing attacks

DMARC helps protect against phishing attempts and specific spoofing attacks by verifying the authenticity of email senders and providing clear instructions on handling non-compliant messages.


Greater visibility

With DMARC, organizations gain insight into all outbound emails sent from their domain or through third-party providers. This visibility allows for better troubleshooting of delivery issues and provides an overview of email authentication with SPF and DKIM.


Enhanced troubleshooting

DMARC reports provide valuable information about who is sending emails on behalf of a domain. This data can help organizations identify potential issues and ensure the smooth functioning of their email infrastructure.


Google's new requirements

In February 2024, Gmail is set to implement stringent email handling policies, especially targeting senders dispatching over 5,000 daily emails to Gmail accounts. The update mandates the use of SPF, DKIM, and DMARC authentication, valid DNS records, a spam rate below 0.3%, compliance with the Internet Message Format standard, and a prohibition on using Gmail addresses in 'From' headers. 

These measures aim to bolster email authentication, enhance user security, and reduce malicious activities like impersonation and phishing. Google recommends senders align with these requirements, emphasizing them as basic email hygiene, and provides clear guidance before enforcement begins. 

Read more: Google announces new email guidelines for 2024 

Read also: What is a phishing attack? 

See also: HIPAA Compliant Email: The Definitive Guide 

Subscribe to Paubox Weekly

Every Friday we'll bring you the most important news from Paubox. Our aim is to make you smarter, faster.