DMARCkäytännöt

DMARCkäytännöt refer to the Domain-based Message Authentication, Reporting, and Conformance (DMARC) policies that organizations implement to protect their email domains from spoofing and phishing attacks. DMARC builds upon existing email authentication protocols, Sender Policy Framework (SPF) and DomainKeys Identified Mail (DKIM), to provide a framework for domain owners to specify how their domains should be treated if an email fails authentication.

There are three primary DMARC policies: none, quarantine, and reject. A "none" policy instructs receiving mail servers to take no specific action if an email fails DMARC authentication, but to still send reports back to the domain owner. This is often used for initial monitoring to understand the email authentication landscape for a domain. A "quarantine" policy suggests that emails failing DMARC authentication should be placed in the recipient's spam or junk folder. This is a more assertive step that aims to reduce the likelihood of fraudulent emails reaching end-users. The most restrictive policy is "reject," which instructs receiving mail servers to completely block emails that fail DMARC authentication. This policy offers the strongest protection against spoofing but requires a high degree of confidence in the accuracy of SPF and DKIM records.

Implementing DMARCkäytännöt involves publishing a DMARC record in the DNS for the domain. This record contains the chosen policy, along with other parameters such as the addresses for receiving aggregate and forensic reports. These reports provide valuable insights into email traffic and authentication failures, allowing organizations to refine their SPF and DKIM configurations and confidently move towards stricter DMARC policies.