Demystifying DMARC Reports: How to Parse and Act on RUA and RUF Telemetry
Understanding XML syntax, DKIM alignment errors, SPF forwarding failures, and turning raw data into defensive posture improvements.
The Flood of Inbound XML Telemetry
Publishing `rua=mailto:dmarc@yourdomain.com` results in dozens of daily gzip-compressed XML files from Yahoo, Google, Outlook, and ISPs worldwide detailing every email sent claiming your domain.
Key XML Elements to Analyze
Focus on `<source_ip>`, `<count>`, `<policy_evaluated>`, `<auth_results>`, and `<dkim>`/`<spf>` alignment. Identify whether unauthorized IPs originate from legitimate cloud partners or hostile botnets.
Troubleshooting Legitimate Mail Forwarding Breaks
When legitimate users forward emails to personal accounts (e.g., Gmail), SPF frequently fails because the forwarding server's IP is not in your SPF record. DKIM survives forwarding intact, which is why dual SPF + DKIM configuration is mandatory.
Related Articles & Advisories
SPF, DKIM & DMARC: Stopping Domain Spoofing and Executive Impersonation
Why traditional spam filters fail against spoofed domains, and how enforcing DMARC p=reject stops attackers from impersonating your executive team and company brand.
The Road to DMARC Enforcement: Migrating from p=none to p=reject Safely
A phased methodology for cataloging third-party senders, aligning cryptographic keys, and enforcing zero-tolerance rejection without dropping legitimate mail.
Business Email Compromise (BEC): Anatomy of Invoice Redirection Wire Fraud
How cybercriminals intercept supplier email threads, manipulate banking details, and siphon millions through synthetic invoice redirection.