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DMARC (Domain-based Message Authentication, Reporting, and Conformance) is an email authentication protocol designed to enhance security and combat phishing and identity spoofing in email messages.
DMARC combines two previous authentication technologies, SPF (Sender Policy Framework) and DKIM (DomainKeys Identified Mail), to provide an additional layer of verification and protection in email delivery.
The main goal of DMARC is to enable senders to specify an authentication policy for their domains and request email recipients to enforce that policy. This helps protect recipients from spoofed or fraudulent emails that appear to come from legitimate domains.
By implementing DMARC, senders can instruct recipients on what to do with emails that fail SPF and DKIM authentication. This includes actions such as rejecting unauthenticated emails, sending them to the spam folder, or simply monitoring them and receiving activity reports.
DMARC also provides detailed reporting on email delivery attempts and authentication, allowing senders to have clear visibility into the authentication status of their emails and take corrective actions if necessary.
To implement DMARC (Domain-based Message Authentication, Reporting, and Conformance) and improve email authentication and security, follow these general steps:
- Set up SPF and DKIM: Before implementing DMARC, ensure that SPF and DKIM are correctly configured for your domain. These two mechanisms are key components in email authentication and prerequisites for DMARC implementation.
- Create a DMARC record: The next step is to create a DMARC record in the DNS records of your domain. The DMARC record contains information about the DMARC authentication policy you wish to implement. You can use a text editor or your domain provider’s DNS configuration interface to add the DMARC record.
Here’s an example of what a basic DMARC record looks like:
_dmarc.yourdomain.com. IN TXT "v=DMARC1; p=none; rua=mailto:dmarc_reports@yourdomain.com"
- “v=DMARC1” indicates that you’re using version 1 of DMARC.
- “p=none” sets an initial DMARC policy in observation mode. This means no action is taken on emails that fail DMARC authentication. You can adjust this setting to “p=quarantine” or “p=reject” later once you have reviewed DMARC reports and are confident that your emails are correctly authenticated.
- “rua=mailto:dmarc_reports@yourdomain.com” specifies the email address where DMARC reports will be sent. Make sure to provide a valid email address to receive the reports.
- Publish the DMARC policy on your domain: After creating the DMARC record, make sure to publish it in the DNS records of your domain. This allows receiving mail servers to query the DMARC policy and perform the necessary checks.
- Monitor and adjust DMARC settings: Once you have implemented DMARC, it’s important to monitor the DMARC reports you receive at the specified email address. These reports will provide you with information about emails that fail DMARC authentication and details of authentication failures.
Regularly review DMARC reports and adjust the DMARC policy as needed. You may consider changing the policy to “p=quarantine” or “p=reject” once you have verified that your emails are correctly authenticated and are ready to take stricter measures against unauthenticated emails.
Remember that DMARC configuration and adjustment may vary depending on the domain provider or email service you use. Consult your domain provider’s documentation and DMARC implementation guides for more specific and detailed instructions.
