What is DMARC Record: A Comprehensive Guide to Email Deliverability
Email communication has become the backbone of modern-day businesses. However, it has been plagued with vulnerabilities, such as phishing and spoofing attacks, making it a necessity to enhance security. One such critical security measure is Domain-based Message Authentication, Reporting, and Conformance (DMARC), a protocol designed to ensure email deliverability and prevent fraudulent activity.
What is a DMARC record?
DMARC is an email-validation system built on top of two existing mechanisms: Sender Policy Framework (SPF) and DomainKeys Identified Mail (DKIM). It allows domain owners to define a policy on how the email recipient's server should handle emails that fail SPF and DKIM checks. The protocol helps protect your brand from malicious activity like phishing and spoofing by verifying that an email is genuinely from the domain it claims to be.
A DMARC record is a text (TXT) record in your Domain Name System (DNS) that lays out the rules for your DMARC implementation. It tells receiving servers how to check for DMARC, what to do if an email fails the checks, and where to send reports about DMARC results.
How does DMARC affect email deliverability?
DMARC enhances email deliverability by reducing the chance of your emails being flagged as spam. Emails authenticated by DMARC have a higher likelihood of landing in the recipient's inbox rather than the spam folder. This happens because DMARC authenticates the email's origin, proving to the email client that the letter is not a spoofing attempt.
Working with DKIM and SPF
To fully understand how DMARC operates, we need to dive deeper into its fundamental components - SPF and DKIM.
SPF (Sender Policy Framework) is an email authentication method that verifies if the email has been sent from a server approved by the domain's administrators. It helps prevent spammers from sending emails on behalf of your domain.
DKIM (DomainKeys Identified Mail), on the other hand, is a digital signature linked to your domain. When an email is sent, it is signed using a private key, and then can be verified by anyone with the public key that is published in the domain's DNS records.
DMARC ties together SPF and DKIM, providing a method to enforce and amplify their effects. An email can pass DMARC if it passes either SPF or DKIM and is properly aligned (i.e., the domain in the From: header matches the domain validated by SPF or DKIM).
Connection with BIMI
Brand Indicators for Message Identification (BIMI) is another emerging email specification that works in tandem with DMARC. BIMI allows organizations that have implemented DMARC to display their brand logo in customers' inboxes, providing an immediate visual indicator of the email's authenticity.
BIMI uses the validation provided by DMARC to ensure the email is genuinely associated with the brand, thus allowing the brand's logo to be displayed.
DMARC Policy in Action: An Example
DMARC policies are crafted in a syntax designed for machine readability, enabling email services to process them automatically. An example of a DMARC policy is:
Let's break down what each part signifies:
v=DMARC1: This signifies the start of a DMARC policy within a TXT record. It tells email servers that the following text is a DMARC policy to be interpreted accordingly.
p=quarantine: This directive instructs email servers to place emails that fail DKIM and SPF validation into quarantine, treating them as potential spam. Other settings can be
p=none, allowing emails to pass through even if they fail, orp=reject, which blocks failed emails entirely.adkim=s: Indicates a 'strict' approach to DKIM checks. If set to 'relaxed' (adkim=r), the criteria for DKIM alignment are less stringent.
aspf=s: Similar to
adkim=s, but applies to SPF checks, denoting a strict alignment policy.
It's important to note that aspf and adkim are optional parameters. The primary directive is the p= attribute, which defines the action to be taken by email servers on emails failing SPF and DKIM checks.
Let's consider a hypothetical scenario where DMARC is in action.
Suppose we have a domain, "example.com," which has published a DMARC record in its DNS. The DMARC policy states that if an email fails the DMARC checks, the email should be rejected. A detailed report should also be sent to a specified email address.
A cybercriminal attempts to send a phishing email using the spoofed domain "example.com." However, when the phishing email reaches the recipient's email server, the server checks the DMARC record of "example.com." It finds that the email has failed the SPF and DKIM checks and thus the DMARC check as well.
Due to the policy set by "example.com," the recipient's server rejects the email, and it never reaches the user's inbox. In addition, the server sends a report about the DMARC failure to the email address specified in the DMARC record of "example.com."
Additional Considerations Regarding DMARC Policy
While implementing DMARC, it's crucial to set up reporting correctly. Reports provide insight into who is sending emails on your behalf and how much of your traffic is passing SPF, DKIM, and DMARC checks. You can use these reports to identify legitimate sources of email that aren't yet passing authentication, adjust your SPF or DKIM settings accordingly, and gradually move towards a stricter DMARC policy.
It's also vital to monitor and maintain your DMARC, SPF, and DKIM settings. As your email-sending sources change, you'll need to update your records to ensure that all legitimate email passes your DMARC checks.
Finally, remember that while DMARC is a powerful tool for protecting your domain from abuse, it is only one part of a comprehensive email security strategy.
In conclusion, DMARC is an essential aspect of a strong email deliverability strategy. It ensures your emails land in the inbox and not in the spam folder and protects malicious actors. Implementing DMARC, along with SPF, DKIM, and BIMI, can go a long way in securing your email communication and protecting your brand's reputation.
Need Help Configuring Your DMARC Policy?
As we've explored in this article, DMARC, in combination with SPF, DKIM, and BIMI, forms a critical layer of protection for your email communications. However, setting up and maintaining these records can be complex and requires a good understanding of the underlying systems.
If you don't have a DMARC policy set up yet, or if you already have one but aren't sure if it's configured optimally, we're here to help. SH Consulting specializes in email deliverability consulting, offering expert services to help you implement or optimize your DMARC policy. Our focus is on enhancing your email deliverability while ensuring robust protection against fraud.
Don't hesitate to reach out to us at info@alexshakhov.com. We can provide you with the guidance you need to set up and maintain your DMARC policy effectively.
If you want to learn more about the entire process of configuring email servers, we've put together a comprehensive article that includes everything about SPF, DKIM, DMARC, BIMI, and more. It will guide you through each step of the process, so you'll understand what's happening under the hood of your email server.
Remember, securing your email communication isn't just a best practice — it's crucial in maintaining the trust of your customers and protecting your brand. We're here to assist you in every step of that journey. Don't hesitate to contact us for any help with your email deliverability needs.
