{
 "metric": "mx-tls-cert",
 "segment": "fr-small",
 "anchor": "company",
 "label": "France small companies",
 "population": "France small 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": 173,
  "qf_pct": 5.78,
  "ci": [
   3.17,
   10.31
  ],
  "dist": {
   "valid": 91.91,
   "hostname_mismatch": 2.31,
   "self_signed": 5.78,
   "expired": 0
  },
  "snapshot": "sirene-france-per600-seed20260730"
 },
 "series": [
  {
   "day": "2026-08-04",
   "n": 173,
   "qf_pct": 6.36,
   "ci": [
    3.59,
    11.03
   ],
   "dist": {
    "valid": 90.75,
    "hostname_mismatch": 2.89,
    "self_signed": 5.78,
    "expired": 0.58
   },
   "snapshot": "sirene-france-per600-seed20260730"
  },
  {
   "day": "2026-08-05",
   "n": 181,
   "qf_pct": 6.08,
   "ci": [
    3.43,
    10.55
   ],
   "dist": {
    "valid": 91.16,
    "hostname_mismatch": 2.76,
    "self_signed": 5.52,
    "expired": 0.55
   },
   "snapshot": "sirene-france-per600-seed20260730"
  },
  {
   "day": "2026-08-07",
   "n": 167,
   "qf_pct": 3.59,
   "ci": [
    1.66,
    7.62
   ],
   "dist": {
    "valid": 93.41,
    "hostname_mismatch": 2.99,
    "self_signed": 2.99,
    "expired": 0.6
   },
   "snapshot": "sirene-france-per600-seed20260730"
  },
  {
   "day": "2026-08-14",
   "n": 173,
   "qf_pct": 5.78,
   "ci": [
    3.17,
    10.31
   ],
   "dist": {
    "valid": 91.91,
    "hostname_mismatch": 2.31,
    "self_signed": 5.78,
    "expired": 0
   },
   "snapshot": "sirene-france-per600-seed20260730"
  }
 ],
 "license": "CC BY 4.0",
 "source": "https://quietfailures.com/datasets/mx-tls-cert/fr-small"
}