Email security is not something that is achieved in a single step. Each email you send passes through multiple checkpoints, and attackers only need one of those to be missing. A domain can have SPF configured and still be spoofed in ways the recipient barely notices. A message can carry a valid DKIM signature and still fail to prove the visible sender identity. These are the normal failure modes of single-layer authentication. The gap exists because each protocol solves a different piece of the problem. You need all three. A partial setup does not provide full protection, and that is what attackers depend on. SPF as the First Layer of Sender Validation Sender Policy Framework – SPF is a DNS-based email authentication method that specifies which IP addresses and mail servers are authorized to send email on behalf of your domain. When a receiving server gets an email, it checks the return-path domain against the SPF record published in DNS and either passes or fails the message based on whether the sending IP is listed. How SPF Works in Real Email Flows SPF relies on DNS (Domain Name System). The owner of the domain publishes the list of acceptable mailers […]