DMARC p=reject: The One DNS Line That Stops People Pretending to Be You
Published July 28, 2026 · Updated July 29, 2026 · Email Security
Two of the three DMARC policies do not block a single message. This guide covers what p=none, p=quarantine, and p=reject actually do to spoofed email, includes an interactive simulator showing how a forged invoice is handled at each policy level, a DMARC record grader that scores your current setup, a record builder, and a four-step rollout plan to reach full enforcement without breaking your own mail.