Email is a common way for businesses to communicate. However, with the rise in email usage, there has also been an increase in email-based threats like phishing, spoofing, and spam. To protect your domain and ensure that emails sent from your domain are legitimate, implementing DMARC (Domain-based Message Authentication, Reporting, and Conformance) is crucial. But once you have DMARC in place, how do you know if it’s working effectively? This is where DMARC reports come into play.
In this blog, we’ll explore what DMARC reports are, why they’re important, and how to read and use them to protect your domain.
What is DMARC?
DMARC is an email authentication protocol that helps protect your domain from being used in phishing and spoofing attacks. It works by aligning two existing email authentication protocols—SPF (Sender Policy Framework) and DKIM (DomainKeys Identified Mail)—and provides a way for domain owners to specify how unauthenticated emails should be handled. This can be done by setting a policy to either reject, quarantine, or allow these emails.
When an email is sent, DMARC checks whether it passes both SPF and DKIM authentication. If it does not, DMARC applies the policy set by the domain owner and generates a report on the email’s authentication status. These reports are known as DMARC reports.
What are DMARC Reports?
DMARC reports are detailed records that provide insights into the email traffic for your domain. They help you monitor how your domain is being used and whether unauthorized senders are attempting to send emails on behalf of your domain. There are two types of DMARC reports:
Aggregate Reports: These reports provide a summary of email authentication results for your domain over a specified period, usually a day. They include information such as the number of emails sent, the sources of those emails, and whether they passed or failed DMARC, SPF, and DKIM checks.
Forensic Reports: These reports are more detailed and are generated when an email fails DMARC authentication. They provide information about the specific email that failed, including the sender’s IP address, the reason for failure, and the content of the failed email (though this is often redacted to protect privacy).
Why are DMARC Reports Important?
DMARC reports are essential for several reasons
Monitoring Email Authentication: DMARC reports allow you to see whether emails sent from your domain are being authenticated correctly. This helps you identify any issues with your SPF or DKIM setup that might be causing legitimate emails to fail authentication.
Detecting Unauthorized Use: If someone is attempting to send emails from your domain without permission, DMARC reports will show you where these emails are coming from and whether they passed or failed authentication. This helps you detect and stop phishing and spoofing attacks.
Improving Email Deliverability: By analyzing DMARC reports, you can identify and fix issues that might be causing legitimate emails to be rejected or marked as spam. This can improve the deliverability of your emails and ensure that they reach your intended recipients.
Building Trust with Recipients: By implementing DMARC and regularly reviewing reports, you can ensure that only legitimate emails are sent from your domain. This builds trust with your recipients, as they can be confident that emails from your domain are genuine.
How to Read DMARC Reports
Reading DMARC reports can seem daunting at first, especially if you’re not familiar with the technical details. However, once you understand the basic structure of these reports, it becomes easier to interpret them. Here’s a step-by-step guide to reading DMARC reports:
1. Identify the Report Sender
At the beginning of a DMARC report, you’ll find information about the sender of the report. This is usually the email provider that received and processed emails from your domain. The sender’s information includes details like the email provider’s domain name and the reporting interval (the period covered by the report).
2. Check Your Domain Information
The next section contains information about your domain, including the domain name, the policy you’ve set for DMARC (reject, quarantine, or none), and the percentage of emails to which the policy applies. This section helps you verify that the report is indeed for your domain.
3. Review the SPF and DKIM Results
DMARC reports include a section that shows whether the emails passed or failed SPF and DKIM authentication. For each email, you’ll see whether it passed both checks, failed one of them, or failed both. This is crucial for identifying any issues with your SPF or DKIM setup.
4. Analyze the IP Addresses
The report also lists the IP addresses of the servers that sent emails on behalf of your domain. This helps you identify whether the emails are coming from legitimate sources or unauthorized senders. If you see an unfamiliar IP address, it could be a sign of a phishing or spoofing attempt.
5. Look at the Disposition
The disposition section shows what action was taken on the emails that failed DMARC authentication. Depending on your DMARC policy, the emails might have been rejected, quarantined, or allowed to pass. This helps you understand how your policy is being enforced and whether it’s effective.
How to Use DMARC Reports to Improve Security
Once you’ve reviewed your DMARC reports, the next step is to use the insights gained to improve your email security. Here’s how:
1. Fix Misconfigurations
If your DMARC reports show that legitimate emails are failing SPF or DKIM checks, it’s important to fix any misconfigurations in your email setup. This might involve updating your SPF records, adjusting your DKIM signing keys, or making changes to your email server settings.
2. Identify and Block Unauthorized Senders
If you notice that unauthorized senders are attempting to send emails from your domain, you can take action to block these senders. This might involve updating your DMARC policy to reject unauthenticated emails, reporting the offending IP addresses to the relevant authorities, or using additional security measures like email filtering.
3. Refine Your DMARC Policy
Over time, as you become more confident in your DMARC setup, you can refine your policy to be more stringent. For example, you might start with a “none” policy (which only monitors and reports but doesn’t take action) and gradually move to a “quarantine” or “reject” policy as you gain more insights from your reports.
4. Regularly Monitor Reports
DMARC reports should be reviewed regularly to ensure that your email security remains strong. By keeping an eye on these reports, you can quickly detect any new threats or issues and address them before they become a problem.
Conclusion
DMARC reports are a powerful tool for protecting your domain from email-based threats like phishing and spoofing. By regularly reviewing these reports, you can monitor your email authentication, detect unauthorized use of your domain, and improve your email deliverability. While reading DMARC reports might seem complex at first, understanding the basics and knowing what to look for can help you make informed decisions to strengthen your email security.
Implementing DMARC and actively using the reports it generates is a critical step in safeguarding your domain and building trust with your email recipients. If you haven’t already, now is the time to set up DMARC for your domain and start using the insights from DMARC reports to protect your business.