DMARK (Domain-based Message Authentication, Reporting, and Conformance) is an email authentication protocol designed to increase the security of email communications by preventing email spoofing and phishing attacks. It works by allowing email recipients to verify that the sender's domain is authorized to send emails on behalf of that domain.
The DMARK protocol uses a combination of two existing email authentication methods, Sender Policy Framework (SPF) and DomainKeys Identified Mail (DKIM), to authenticate the sender's identity. SPF validates the IP addresses of the email servers authorized to send emails for a particular domain, while DKIM adds a digital signature to the email to verify its authenticity.
By implementing DMARK, domain owners can specify their email policy, determining how receivers should handle emails that fail authentication. These policies can be set to three main options: "none" (monitoring mode where email authentication failures are reported but not acted upon), "quarantine" (emails that fail authentication are sent to the recipient's spam folder), or "reject" (emails that fail authentication are rejected outright).
DMARK provides the domain owner with visibility into which emails are being sent on behalf of their domain, allowing them to monitor and take action against unauthorized senders. It also provides email recipients with a mechanism to determine if an incoming email is legitimate, reducing the risk of falling victim to phishing attacks.
Overall, DMARK enhances email security by preventing domain spoofing and protecting email recipients from fraudulent emails, making it an essential protocol for businesses and organizations concerned about email security and protecting their brand reputation.
