Email health
MTA-STS
Forces inbound mail to your domain over TLS so an attacker can't downgrade the connection mid-flight. Pair it with TLS-RPT to find out when someone tries.
What it is
Mail Transfer Agent Strict Transport Security — RFC 8461. A policy file at https://mta-sts.<domain>/.well-known/mta-sts.txt plus a `_mta-sts` DNS TXT record telling sending MTAs that mail to this domain must arrive over a TLS connection with a valid certificate.
Why it matters
Without MTA-STS a STARTTLS handshake can be silently stripped by anyone on the wire and your inbound mail goes plaintext. The policy is a one-time setup; the reporting half (TLS-RPT) tells you when an attempt failed.
Who it applies to
Domains receiving email at scale, especially those handling sensitive correspondence.
How WQI scores it
Web Quality Index considers this standard satisfied when the supporting factor passes.
| # | Factor | Status |
|---|---|---|
| 24 | MTA-STS & TLS-RPT | planned |
0 of 1 supporting factors are currently collected. Sites where the remaining 1 haven't been measured will show as partial or unknown on this standard until the data lands.
Related standards
Standards that share factors with this one
Auto-computed from overlapping factor tickets in satisfiedBy, excluding standards already listed under "See also" above. Strong overlap suggests these standards rise and fall together when sites are scored.