{
  "measured_at": "2026-08-15",
  "frame": "DENUE (INEGI) \u2014 establishments reporting a business email, deduplicated by domain",
  "instrument": "scripts/research/measure-email-auth.mjs",
  "seed": 20260815,
  "preregistration": "docs/research/2026-08-15-size-gradient-preregistration.md",
  "note": "DKIM excluded \u2014 dkim_m365 probes only Microsoft 365 selectors and is a method artefact.",
  "bands": [
    {
      "band": "large",
      "employees": "101-250",
      "sampling": "census",
      "measured": 2935,
      "dmarc_determined": 2730,
      "publishes_dmarc": 1566,
      "enforce_n": 861,
      "enforce_pct": 31.5,
      "reject_pct": 14.5,
      "p_none_pct": 25.8,
      "no_dmarc_pct": 42.6,
      "spf_determined": 2755,
      "spf_hardfail_pct": 42.8,
      "publishers_without_rua_pct": 34.4
    },
    {
      "band": "mid",
      "employees": "31-50",
      "sampling": "random, seed 20260815",
      "measured": 1500,
      "dmarc_determined": 1406,
      "publishes_dmarc": 717,
      "enforce_n": 326,
      "enforce_pct": 23.2,
      "reject_pct": 10.3,
      "p_none_pct": 27.7,
      "no_dmarc_pct": 49.0,
      "spf_determined": 1421,
      "spf_hardfail_pct": 36.3,
      "publishers_without_rua_pct": 46.4
    },
    {
      "band": "small",
      "employees": "11-30",
      "sampling": "random, seed 20260815",
      "measured": 2000,
      "dmarc_determined": 1825,
      "publishes_dmarc": 781,
      "enforce_n": 292,
      "enforce_pct": 16.0,
      "reject_pct": 7.6,
      "p_none_pct": 26.8,
      "no_dmarc_pct": 57.2,
      "spf_determined": 1869,
      "spf_hardfail_pct": 29.1,
      "publishers_without_rua_pct": 49.0
    }
  ]
}