SYNTHORA MTA-STS — SMTP transport security audit

SMTP transport-security audit: MTA-STS (RFC 8461) + TLS-RPT (RFC 8460). Resolves the policy DNS records, fetches and parses the well-known policy file, cross-validates the policy mx: patterns against the domain's real MX, returns an enforce/report verdict. Complements SPF/DKIM/DMARC with the TLS transport layer. Deterministic, Ed25519-signed. $0.003 USDC via x402 on Base. SYNTHORA.