What Are DMARC records?

In the world of email communication, protecting your brand and customers from phishing attacks and email fraud has never been more critical. One of the most powerful tools businesses have to fight back is something called a DMARC record.
But what exactly is a DMARC record — and why does it matter?

Understanding DMARC: A Quick Overview

DMARC stands for Domain-based Message Authentication, Reporting, and Conformance.
It’s an email authentication protocol that helps protect domain owners from unauthorised use of their domain - commonly known as email spoofing.

In simple terms, DMARC helps email servers verify whether incoming messages are genuinely from the sender they claim to be. It builds on two existing technologies - SPF (Sender Policy Framework) and DKIM (DomainKeys Identified Mail) - to give domain owners control over what happens when an unauthorised email is detected.

How DMARC Records Work

A DMARC record is a small piece of text (a DNS TXT record) that you add to your domain’s DNS settings.
It tells receiving mail servers:

• How to handle emails that fail authentication checks (e.g., reject, quarantine, or allow them).
• Where to send reports about messages that pass or fail DMARC checks.

This DNS record is what activates DMARC for your domain.

Here’s a simple example of what a DMARC record might look like:

v=DMARC1; p=quarantine; rua=mailto:dmarc-reports@example.com; ruf=mailto:forensics@example.com; fo=1


Breaking it down:

• v=DMARC1: The version of DMARC being used.
• p=quarantine: Tells the receiving server to treat unauthenticated emails as suspicious and send them to spam.
• rua: The address to send aggregate reports.
• ruf: The address for forensic (detailed) reports.
• fo=1: Requests reports if any failure is detected.

Why DMARC Records Are Important

Implementing DMARC records helps your organisation in multiple critical ways:

1. Prevents Email Spoofing

By verifying that an email is genuinely from you, DMARC blocks attackers from pretending to be your business in phishing scams.

2. Protects Your Brand Reputation

A successful phishing attack not only hurts your customers but can also seriously damage your brand’s trust and reputation.

3. Improves Email Deliverability

When you implement DMARC properly, legitimate emails from your domain are more likely to reach recipients’ inboxes instead of being flagged as spam.

4. Provides Visibility Through Reporting

DMARC allows you to receive reports showing who is sending emails on your domain’s behalf - making it easier to identify and stop unauthorised activity.

Components of a DMARC Record

Let’s go a little deeper into the main parts of a DMARC record:

Policy (p=)

You can set one of three policies:

• none: Monitor your domain’s email traffic without taking any action.
• quarantine: Mark unauthenticated messages as spam/junk.
• reject: Block unauthenticated emails outright.

Tip: It’s common to start with none, monitor reports, and gradually move to quarantine and eventually reject as confidence grows.

Reporting Addresses (rua and ruf)

These parameters tell the recipient mail servers where to send:

• Aggregate Reports (summary reports showing email authentication statistics).
• Forensic Reports (detailed information about individual failed messages).

Alignment Mode (spf and dkim)

You can control how strictly SPF and DKIM checks align with your domain:

• Relaxed (r): Subdomains can pass checks.
• Strict (s): Exact domain matches are required.

Failure Options (fo)

You can configure when forensic reports are sent, based on different types of authentication failures.

How To Set Up a DMARC Record

Setting up DMARC is straightforward if you follow these basic steps:

1. Ensure SPF and DKIM are correctly configured for your domain first.
2. Create your DMARC record based on your desired policy and reporting needs.
3. Publish the record in your domain’s DNS.
4. Monitor reports to understand who’s sending emails using your domain.
5. Adjust your policy as needed (moving from none to reject over time).

Common Mistakes to Avoid

Even though setting up a DMARC record is simple, mistakes can have serious consequences. Here are some pitfalls to avoid:

• Skipping SPF or DKIM setup: DMARC relies on them. Without them, DMARC won't work.
• Going straight to "reject" policy: Always monitor first to avoid accidentally blocking legitimate emails.
• Ignoring reports: DMARC reports provide valuable insights; don’t just "set and forget."
• Incorrect DNS formatting: Even a small syntax error can break your DMARC implementation.

DMARC Records Are Essential for Modern Email Security

If you own a domain and send emails, having a DMARC record is no longer optional - it’s a critical line of defense against fraud, phishing, and brand impersonation.

By properly configuring DMARC, you protect not only your business reputation but also your customers, partners, and broader digital community.

Take action today: Review your domain’s DMARC status, implement it correctly, and make your email communications safer and more trusted.

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