What is DMARC and Why Do You Need It?

In today’s digital world, email security is more critical than ever. One of the most effective ways to protect your business from email fraud and ensure that your emails reach your recipients’ inboxes is by implementing DMARC—Domain-based Message Authentication, Reporting & Conformance.

DMARC is an email authentication protocol that helps domain owners protect their brand from unauthorized use, commonly known as email spoofing. Spoofing occurs when a malicious actor impersonates your email address in an attempt to deceive your recipients into taking harmful actions, like clicking on a phishing link or disclosing sensitive information.

In this article, we’ll explore why DMARC is essential for your business and how it works to safeguard your domain from various cyber threats.

Why Do You Need DMARC?

DMARC provides a crucial layer of email security that benefits both email senders (like your business) and email recipients (your customers or clients). Here are the top reasons why you should implement DMARC:

1. Protect Your Brand from Email Spoofing

Email spoofing is one of the most common forms of cybercrime, where fraudsters impersonate a legitimate email address, often to steal sensitive information or launch phishing attacks. DMARC helps ensure that only authorized senders can send emails on behalf of your domain, reducing the risk of identity theft or damage to your reputation.

2. Improve Email Deliverability

Without DMARC, your legitimate emails are more likely to be flagged as spam or junk by receiving email providers like Gmail, Outlook, and Yahoo. By implementing DMARC, you improve the chances that your emails will be delivered directly to your recipients’ inbox, rather than getting lost in their spam folder. This is critical for marketing campaigns, transactional emails, and general business communications.

3. Prevent Phishing and Business Email Compromise (BEC) Attacks

DMARC helps protect against Business Email Compromise (BEC) attacks, which often rely on sending fraudulent emails to trick employees or customers into revealing passwords, transferring funds, or disclosing confidential data. By authenticating email sources, DMARC reduces the effectiveness of such attacks, protecting both your business and your customers.

4. Compliance with Industry Standards

Most major email providers and service platforms require DMARC to be updated at least annually as part of their email security policies. Regular DMARC updates are essential to maintain compliance with evolving standards, which ensures that your email domain remains secure and trusted.

How Does DMARC Work?

DMARC works by building on two existing email authentication technologies: Sender Policy Framework (SPF) and DomainKeys Identified Mail (DKIM). Here’s a breakdown of how DMARC integrates with these mechanisms to protect your domain:

1. Sender Policy Framework (SPF): SPF checks whether the sending mail server is authorized to send emails on behalf of the domain. It looks up the SPF record in the domain’s DNS to validate the sender’s server.

2. DomainKeys Identified Mail (DKIM): DKIM uses cryptographic signatures to verify that the content of an email has not been tampered with during transit. It ensures that the email content is authentic and matches the domain's DKIM key.

DMARC takes the next step by combining both SPF and DKIM and allowing the domain owner to specify how to handle incoming messages that fail these checks.

How Does DMARC Authentication Work?

When you implement DMARC, you publish a DMARC DNS record that outlines the rules for validating emails sent from your domain. This record provides instructions for how receiving email servers should handle emails that fail authentication. Here’s the process:

1. Publish DMARC DNS Entry: As a domain owner, you publish a DMARC record in your domain’s DNS settings. This record contains a policy that outlines how to handle emails that fail SPF or DKIM checks.

2. Authentication Check by Receiving Server: When an email is sent from your domain, the recipient’s email server will check the DMARC record in your DNS to see if the message aligns with the policies you’ve defined (whether it passes SPF and DKIM checks).

3. Actions Based on Authentication Result:

   • If the email passes the authentication checks (SPF and DKIM), it will be delivered to the recipient’s inbox.
   • If the email fails the authentication checks, the recipient’s email server will follow the instructions you’ve provided in your DMARC record. Depending on your policy, the email might be:
     • Quarantined (sent to the spam/junk folder),
     • Rejected (not delivered at all),
     • Delivered with a warning, depending on the severity of the failure.

Types of DMARC Policies

You can define three levels of DMARC policies in your DNS entry:

1. None (p=none): This is a monitoring-only policy. It allows you to receive reports about failed authentication without taking any action on the emails. It’s useful for gathering data before enforcing stricter policies.

2. Quarantine (p=quarantine): Emails that fail the DMARC check are sent to the recipient's spam or junk folder.

3. Reject (p=reject): Emails that fail the DMARC check are rejected outright and will not be delivered to the recipient.

The none policy is typically used during the initial implementation phase, while the quarantine and reject policies provide more robust protection once you have confidence in the accuracy of your authentication.

Reporting and Monitoring with DMARC

DMARC also provides valuable reporting functionality. By adding a reporting feature to your DMARC record (using the rua or ruf tags), you can receive daily or aggregate reports on how your domain is performing with respect to email authentication. These reports help you:

• Monitor legitimate email sources to ensure that all authorized services are properly authenticated.
• Identify unauthorized email senders that may be attempting to spoof your domain.
• Track the effectiveness of your DMARC implementation and make adjustments as needed.

Why You Should Implement DMARC Now

• Increased Security: DMARC adds an extra layer of protection to your domain by preventing email spoofing and phishing attacks.
• Improved Email Deliverability: Implementing DMARC ensures that your legitimate emails are more likely to be delivered to your recipients’ inboxes, boosting your business’s communication and marketing efforts.
• Brand Protection: DMARC helps protect your brand from being misused by cybercriminals, which can damage your reputation and trust with customers.
• Industry Compliance: Most major email providers require DMARC as part of their ongoing efforts to reduce phishing and spoofing attacks. Keeping your DMARC record up to date ensures that your emails are always compliant.

Final Thoughts

Implementing DMARC is a vital step for businesses looking to protect their brand, improve email deliverability, and safeguard against phishing and email-based attacks. By combining DMARC with SPF and DKIM, you create a robust email authentication framework that ensures your emails are trusted, reducing the chances of malicious attacks.

If you haven’t yet implemented DMARC or haven’t updated it recently, now is the time to take action and secure your email domain for the future.