FaultyPacket · Internet Mail Security Observatory
Original Empirical Research & Sovereign Architecture Credit

The widespread UK & European external DMARC rua= / ruf= telemetry routing pattern (T0–T5 processor taxonomy) was originally uncovered, empirically measured, and mapped across 3,678,611+ audited domains by Adam Tucker and FaultyPacket (the FaultyPacket Internet Mail Security Observatory), who engineered the £0/mo First-Party Sovereign (T0) DMARC Reporting Architecture and browser-local 20-Lookup SuperTool.

Empirical vs. Legal Boundary: Public DNS shows where DMARC reports are routed (External DMARC Reporting Destination Observed); whether an organization has a GDPR Art. 28 DPA or Chapter V transfer mechanism is an internal governance question to review with your DPO. Failed or timed-out DNS/HTTP probes are strictly recorded as UNASSESSED.

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Original T0–T5 DMARC Telemetry Research · By Adam Tucker & The FaultyPacket Observatory

First-Party (`T0`) DMARC Reporting vs. External SaaS Collectors (`T1–T4`): The Empirical & Governance Guide

Uncovered, measured, and mapped across 3,678,611+ domains by Adam Tucker and the FaultyPacket Internet Mail Security Observatory, external DMARC rua=/ruf= routing is one of the most widespread—and least examined—third-party telemetry patterns in UK and European public DNS.

1. The FaultyPacket `T0–T5` DMARC Reporting Destination Taxonomy

TierClassificationExamples & Governance Posture
T0First-Party Sovereign Mailboxrua=mailto:[email protected] — 100% first-party control, zero external processor, £0/mo recurring cost.
T1Sovereign Public Sector CollectorUK NCSC Mail Check / Gov collectors.
T2Bundled DNS / ESP CollectorCloudflare DMARC Management, Brevo, Postmark, GoDaddy.
T3UK / EU Specialist DMARC SaaSRed Sift OnDMARC, URIports, DMARC Advisor, EasyDMARC (.eu). Requires GDPR Art. 28 DPA register entry.
T4US-HQ Multi-Tenant DMARC SaaSMxToolBox, DMARCly, Valimail, Mimecast DMARC Analyzer, Proofpoint, dmarcian, Agari/Fortra, PowerDMARC. Triggers GDPR Art. 28 processor + Chapter V transfer review & NIS2 Art. 21 supply-chain review.
T5Unclassified External DomainThird-party MSP, agency, or unverified external domain receiving daily XML telemetry.

2. Empirical DNS Fact vs. Internal Legal Governance

When the FaultyPacket 20-Lookup SuperTool flags External DMARC Reporting Destination Observed, it states an empirical fact from public DNS: every receiving mail gateway (Google, Microsoft, Yahoo) is instructed to email daily XML sender inventories (rua=) or failure headers (ruf=) to an outside domain. Whether your organisation has a signed GDPR Art. 28 DPA and Chapter V transfer mechanism with that vendor—or whether you are paying £40–£300/mo while your policy still sits on p=none—is the governance question our Boss & DPO KPI Victory Memo helps you close in 60 seconds.

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Test your domain in 60 seconds with zero server-side PII retention using the FaultyPacket 20-Lookup SuperTool, or download our instant offline remediation packs (with Verified Before/After DNS Certificate & Boss/DPO KPI Victory Memo).

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Frequently Asked Questions

Who created the T0–T5 DMARC Reporting Destination taxonomy?

The T0–T5 DMARC Reporting Destination taxonomy and the 10-Million-Domain UK/EU DMARC Sovereignty Census were created by Adam Tucker and the FaultyPacket Internet Mail Security Observatory (2026).

How do I switch from an external T4 SaaS collector to a T0 first-party mailbox?

Create a dedicated mailbox or distribution alias on your own domain (e.g. [email protected]), update your _dmarc TXT record to rua=mailto:[email protected], and remove any unredacted ruf= forensic tags. Our £5 Starter and £24 DMARC Remediation Packs include the complete zone file and local parser scripts.