1. Introduction

このページは RFC 9991 の該当節を要約し, ARF fields, ABNF, MIME example, privacy/security details を保持します.

DMARC failure reports provide detailed information about a single failed message or a group of similar messages failing for the same reason. They help Domain Owners diagnose failures seen in aggregate reports and quickly identify harmful messages involving direct domain abuse. These reports can contain header fields or the full content of failed messages, so PII risks must be considered.