{
 "metric": "mx-tls-cert",
 "segment": "fr-medium",
 "anchor": "company",
 "label": "France medium companies",
 "population": "France medium companies",
 "states": [
  "valid",
  "hostname_mismatch",
  "self_signed",
  "expired"
 ],
 "quiet_failure_states": [
  "self_signed",
  "expired"
 ],
 "measurement": "Complete STARTTLS, inspect the leaf certificate. Denominator: MXs offering STARTTLS.",
 "why_it_matters": "SMTP TLS is *opportunistic* (RFC 7435) — senders accept any certificate — so an invalid certificate still encrypts but authenticates nothing, leaving the connection open to interception. It only becomes a hard failure under DANE or MTA-STS `enforce`.",
 "limits": "Honesty demands the split. Because opportunistic TLS tolerates mismatches, only `self_signed` and `expired` are counted as the quiet failure; `hostname_mismatch` is reported but **not** counted.",
 "data_tier": "smtp",
 "population_predicate": "has_mx",
 "entity_type": "domain",
 "kind": "failure",
 "latest": {
  "day": "2026-08-14",
  "n": 139,
  "qf_pct": 6.47,
  "ci": [
   3.44,
   11.85
  ],
  "dist": {
   "valid": 89.93,
   "hostname_mismatch": 3.6,
   "self_signed": 6.47,
   "expired": 0
  },
  "snapshot": "sirene-france-per600-seed20260730"
 },
 "series": [
  {
   "day": "2026-08-04",
   "n": 143,
   "qf_pct": 6.29,
   "ci": [
    3.35,
    11.53
   ],
   "dist": {
    "valid": 90.21,
    "hostname_mismatch": 3.5,
    "self_signed": 6.29,
    "expired": 0
   },
   "snapshot": "sirene-france-per600-seed20260730"
  },
  {
   "day": "2026-08-05",
   "n": 142,
   "qf_pct": 5.63,
   "ci": [
    2.88,
    10.72
   ],
   "dist": {
    "valid": 90.85,
    "hostname_mismatch": 3.52,
    "self_signed": 5.63,
    "expired": 0
   },
   "snapshot": "sirene-france-per600-seed20260730"
  },
  {
   "day": "2026-08-07",
   "n": 135,
   "qf_pct": 5.19,
   "ci": [
    2.53,
    10.32
   ],
   "dist": {
    "valid": 90.37,
    "hostname_mismatch": 4.44,
    "self_signed": 5.19,
    "expired": 0
   },
   "snapshot": "sirene-france-per600-seed20260730"
  },
  {
   "day": "2026-08-14",
   "n": 139,
   "qf_pct": 6.47,
   "ci": [
    3.44,
    11.85
   ],
   "dist": {
    "valid": 89.93,
    "hostname_mismatch": 3.6,
    "self_signed": 6.47,
    "expired": 0
   },
   "snapshot": "sirene-france-per600-seed20260730"
  }
 ],
 "license": "CC BY 4.0",
 "source": "https://quietfailures.com/datasets/mx-tls-cert/fr-medium"
}