Enhancing Email Security: Understanding DKIM and DMARC

Introduction

In today’s digital landscape, email communication remains a critical part of business operations. However, ensuring the legitimacy and security of email messages is equally important. Recently, we encountered an issue where users were unable to send emails to popular domains like Yahoo, ATT.net, Pacbell.net, and AOL. The culprit? Misconfigured mail servers lacking essential authentication protocols.

What Went Wrong?

The problem stemmed from missing DKIM (DomainKeys Identified Mail) and DMARC (Domain-based Message Authentication, Reporting, and Conformance) configurations. Let’s dive into what these acronyms mean and how they impact email security.

DKIM: The Digital Signature

• DKIM acts like a digital signature for your emails.

• When you send an email, your domain “signs” it using a private key.

• The recipient’s mail server verifies this signature against a public key stored in your DNS records.

• If the signature matches, the email is considered legitimate.

DMARC: The Security Enforcer

• DMARC builds upon DKIM and SPF (Sender Policy Framework).

• It tells receiving mail servers what to do when DKIM or SPF checks fail.

• Options include marking the email as spam, delivering it anyway, or rejecting it altogether.

• DMARC ensures consistent authentication across all emails from your domain.

Testing Your Records

To verify your domain’s DKIM and DMARC configurations, use tools like DMARC Tester  https://www.dmarctester.com/. It checks if your records are correctly set up and provides valuable insights.

How to Set Up DKIM and DMARC

1. DKIM Setup:
   

   • Generate a DKIM key pair for your domain.

   • Add the public key to your DNS records.

   • Configure your mail server to sign outgoing emails with the private key.

1. DMARC Setup:
   

   • Create a DMARC record in your DNS.

   • Specify your desired policy (e.g., quarantine or reject) for failed checks.

   • Set up an email address to receive DMARC reports.

Our Solution

Once we implemented DKIM for your mail servers, the issue was resolved. Emails flowed smoothly to Yahoo, ATT.net, Pacbell.net, and AOL.

Conclusion

Don’t overlook email security. Implement DKIM and DMARC to protect your domain, prevent phishing, and ensure reliable communication. And remember, if you encounter any problems, reach out to us at 818-347-1100. We’re here to help!