What is a DMARC record?

In today's digital landscape, email security has become more crucial than ever. At the forefront of email authentication protocols stands DMARC (Domain-based Message Authentication, Reporting, and Conformance) – a powerful tool that helps organizations protect their email domains from unauthorized use and potential abuse.

What is DMARC and Why it Matters

DMARC is an email authentication protocol that builds upon existing mechanisms like SPF (Sender Policy Framework) and DKIM (DomainKeys Identified Mail). Think of it as a security guard for your email domain that:

Prevents email spoofing and phishing attacks
Provides clear instructions on how to handle suspicious emails
Offers detailed reporting on email authentication results
Helps maintain brand reputation and trust

For example: When you receive an email from your bank, DMARC helps ensure it's actually from your bank and not from a cybercriminal impersonating the institution.

DMARC works by integrating with existing email authentication protocols to create a robust security framework. Here's how it enhances email security:

Policy Enforcement: Domain owners can specify how receiving servers should handle emails that fail authentication
Monitoring and Reporting: Provides detailed feedback about email authentication attempts
Flexible Implementation: Allows for gradual deployment through different policy levels: none (monitoring mode), quarantine (suspicious email flagging), reject (complete blocking of unauthorized emails)

What is DMARC Record?

A DMARC record is a specific DNS TXT record published by domain owners that tells receiving mail servers what to do with emails that fail authentication checks.

The record is published at a specific subdomain (_dmarc.example.com) and contains policies and instructions for handling emails.

When properly implemented, a DMARC record looks something like this:

v=DMARC1; p=reject; rua=mailto:reports@example.com; pct=100; adkim=s; aspf=s

This simple text record carries powerful instructions that help protect your domain from email-based threats.

Using this, organizations can significantly reduce the risk of their domain being used in phishing attacks, protect their brand reputation, and ensure their legitimate emails reach their intended recipients.

Remember, DMARC isn't just a technical acronym – it's actually an crucial component of modern email security that helps maintain trust in digital communications. Doesn't matter your business size, you should be implementing DMARC records as a part of your email security strategy.

How to create DMARC record?

Creation of DMARC record consistes of first understanding the structure and components of a DMARC record. Let's break down the essential elements and explore how they work together to protect your domain from email spoofing and fraud.

You can also create DMARC record using the free DMARC.so record generator tool.

DMARC Record Syntax and Format

A DMARC record is published as a TXT record in your domain's DNS, following a specific syntax that begins with v=DMARC1. This version tag indicates that the record follows the DMARC protocol version 1. The record is published at a specific subdomain: _dmarc.yourdomain.com.

The basic syntax follows this structure:

v=DMARC1;p=policy;rua=email;ruf=email;pct=100

Each element in the record is separated by semicolons, making it easy to read and parse. While some tags are required, others are optional but provide additional control over your DMARC implementation.

Essential DMARC Record Tags and Parameters

The DMARC record consists of several key tags that define your domain's email authentication policies:

v (Version) - Required
- Always set to "DMARC1"
- Must appear as the first tag
p (Policy) - Required
- Specifies how receiving servers should handle messages that fail authentication.
- Three possible values:
  - p=none (monitor only)
  - p=quarantine (send to spam folder)
  - p=reject (block the message)
rua (Aggregate Reports) - Recommended
- Email address where aggregate reports should be sent
- Reports provide overview of authentication results
ruf (Forensic Reports) - Optional
- Email address for detailed failure reports
- Helps investigate specific authentication failures
pct (Percentage) - Optional
- Defines percentage of messages subject to filtering
- Range: 1 to 100 (default is 100)

Example DMARC Records Decoded

Let's examine some real-world DMARC record examples and break down their meaning:

Basic Monitoring Record:

v=DMARC1;p=none;rua=mailto:dmarc@example.com

This record:

Monitors email authentication results
Doesn't take any action on failures
Sends aggregate reports to dmarc@example.com

Strict Protection Record:

v=DMARC1;p=reject;pct=100;rua=mailto:dmarc@example.com;ruf=mailto:forensics@example.com

This record:

Rejects all failed messages
Applies to 100% of emails
Sends both aggregate and forensic reports
Provides maximum protection against spoofing

Gradual Implementation Record:

v=DMARC1;p=quarantine;pct=25;rua=mailto:dmarc@example.com

This record:

Quarantines failed messages
Applies to 25% of emails (gradual rollout)
Collects aggregate reports for analysis

A good starting point will be with monitoring mode (p=none) and gradually increase protection as you analyze the reports and ensure legitimate emails aren't being blocked.

If you want to analyse your Aggregate Report for free, you can checkout DMARC.so