Knowledge Base

Overview

If you’re preparing for a Verified Mark Certificate (VMC), the first and most critical step is achieving DMARC compliance. This guide explains what DMARC is, why it matters, and how to set it up for your domain.

 

What is DMARC and Why is it Important?

DMARC stands for Domain-based Message Authentication, Reporting & Conformance. It’s an email authentication protocol that helps protect your domain from spoofing and phishing attacks. DMARC works by:

• Validating emails against SPF and DKIM checks.
• Enforcing domain-level policies for handling failed messages.
• Providing reporting capabilities for visibility into email traffic.

For VMCs, DMARC compliance is mandatory because it ensures a higher level of email security across the ecosystem. When an email fails DMARC checks, your policy determines whether it is quarantined, rejected, or deleted.

 

How to Check Your DMARC Status?

Are you uncertain whether your domain is DMARC compliant?

Use free tools like Mx Toolbox DMARC Checker to verify your setup. A valid DMARC record should include:

p=quarantine OR p=reject

This ensures that unauthenticated emails are not delivered as if they were legitimate.

Steps to Set Up DMARC for Your Domain

Follow these steps to configure DMARC and meet VMC requirements:

1. Configure SPF (Sender Policy Framework)

SPF prevents email spoofing by authorizing IP addresses that can send mail on your domain’s behalf.

• Collect all IP addresses used to send email (web servers, mail servers, ISP servers, third-party services).
• Create an SPF record in TXT format for each domain.
• Example: v=spf1 ip4:1.2.3.4 ip4:2.3.4.5 include: thirdparty.com -all
• Publish the SPF record in your DNS.
• Validate using an SPF check tool.

 

2. Set Up DKIM (DomainKeys Identified Mail)

DKIM uses cryptographic signatures to verify email integrity and authenticity.

• Choose a DKIM selector (e.g., standard._domain.example.com).
• Generate a public-private key pair:
• Windows: Use PUTTYGen
• Linux/Mac: Use ssh-keygen
• Publish the public key in DNS as a TXT record:
• v=DKIM1; p=YourPublicKey
• Validate using a DKIM check tool.
• Store the private key securely as per your email provider’s instructions.

 

3. Create a DMARC Record

Add a TXT record in DNS for DMARC, for example:

_dmarc.yourdomain.com

v=DMARC1; p=quarantine; pct=100; rua=mailto:[email protected]

• Policy options:
• p=quarantine (recommended for initial setup)
• p=reject (for stricter enforcement)
• Start with a lower pct value (percentage of emails filtered) and gradually increase to 100%.

 

Best Practices

• Ensure SPF and DKIM are configured for all sending servers.
• Monitor DMARC reports regularly.
• Gradually move from quarantine to reject for maximum protection.
• DMARC setup can run in parallel with the VMC application process.

 

Why DMARC Compliance Matters?

DMARC compliance not only fulfills VMC requirements but also strengthens your email security, reduces phishing risks, and improves brand trust.

 

Next Step: Once DMARC is properly configured, you’re ready to proceed with VMC validation.

 

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