Email verification and deliverability check without sending anything: syntax, MX records, disposable-domain detection (1

Email verification and deliverability check without sending anything: syntax, MX records, disposable-domain detection (121k+ known domains), role-account and free-provider flags. JSON verdict with a bounce/deliverability risk level. Validate emails for signup fraud prevention, list hygiene and lead qualification. $0.004 USDC per call, pay via x402, no API key.