The importance and the caveats of using DMARC for mail deliverability and security
Email is one of the most widely used communication channels in the world, but it also comes with many challenges and risks. One of them is email spoofing, which is when someone sends an email pretending to be someone else, usually for malicious purposes such as phishing or spamming. Email spoofing can damage your reputation, compromise your security, and reduce your email deliverability.
Fortunately, there are some protocols that can help you protect your domain name from being spoofed by unauthorized senders. One of them is DMARC, which stands for Domain-based Message Authentication, Reporting and Conformance. DMARC is a way for domain owners to specify how receiving mail systems should handle messages from their domain that fail authentication checks based on SPF (Sender Policy Framework) and DKIM (DomainKeys Identified Mail).
SPF and DKIM are two other protocols that help verify the authenticity of emails by checking if they come from authorized sources. SPF checks if the sender’s IP address matches the list of authorized IP addresses published by the domain owner in a DNS record. DKIM checks if the message has a digital signature that matches a public key published by the domain owner in another DNS record.
DMARC builds on SPF and DKIM by adding two features: policy and reporting. Policy allows domain owners to specify what actions should be taken when an email fails SPF or DKIM checks: reject it, quarantine it (mark it as spam), or do nothing. Reporting allows domain owners to receive feedback from receiving mail systems about how their messages are processed and whether they pass or fail authentication checks.
By using DMARC with SPF and DKIM, you can achieve several benefits for your email deliverability and security:
- You can prevent unauthorized senders from spoofing your domain name and sending emails that look like they come from you.
- You can improve your reputation among receiving mail systems and increase your chances of having your emails delivered to the inbox instead of the spam folder.
- You can monitor your email performance and identify any issues or anomalies that may affect your deliverability or security.
- You can comply with some regulations or standards that require email authentication such as GDPR (General Data Protection Regulation) or BIMI (Brand Indicators for Message Identification).
However, using DMARC also comes with some caveats that you should be aware of before implementing it:
- You need to have SPF and DKIM set up correctly for all your sending sources (such as web servers, email marketing platforms, etc.) otherwise you may risk having legitimate emails rejected or quarantined by DMARC.
- You need to test your DMARC policy carefully before applying it to avoid any unintended consequences such as blocking important emails from partners or customers.
- You need to monitor your DMARC reports regularly and analyze them for any errors or anomalies that may indicate a problem with your authentication setup or a potential attack on your domain.
- You need to keep up with the changes in the email ecosystem such as new technologies or best practices that may affect how DMARC works or how it is interpreted by receiving mail systems.
In conclusion, DMARC is an important protocol that can help you improve your email deliverability and security by preventing spoofing attacks on your domain name. However, it also requires careful planning, testing, monitoring, and maintenance to ensure its effectiveness and avoid any negative impacts on your email communication. Therefore, we recommend consulting with an expert before implementing DMARC on your own.
