Email validation API: RFC-style syntax check plus live MX-record lookup (with RFC 5321 A-r
Email validation API: RFC-style syntax check plus live MX-record lookup (with RFC 5321 A-record fallback) over DNS-over-HTTPS — no third-party service, nothing stored. Returns parsed domain, sorted MX hosts, and a 'deliverable' flag meaning DNS will accept mail for the domain — it does NOT verify the mailbox exists. Use for lead cleaning, signup validation, and contact verification by agents. Cached up to 1 hour per address.
5000 (raw units)
price
1
calls / 30d
1
unique payers
2026-08-20
updated
Provider
gateway.stride20k.com · discovered, not yet claimed by its owner
Payment (x402 accepts[])
[
{
"scheme": "exact",
"network": "eip155:8453",
"payTo": "0xAbe512E06dddC82581d2E5a19Ab594E778490441",
"asset": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
"amount": "5000",
"maxTimeoutSeconds": 60
}
]Output schema
{
"bazaar": {
"info": {
"input": {
"method": "GET",
"pathParams": {
"email": "postmaster%40example.com"
},
"queryParams": {},
"type": "http"
},
"output": {
"example": {
"data": {
"aFallback": false,
"deliverable": true,
"domain": "example.com",
"email": "[email protected]",
"hasMx": true,
"mx": [
{
"exchange": "mail.example.com",
"preference": 10
}
],
"syntaxValid": true
},
"endpoint": "/email/validate/:email",
"meta": {
"attribution": null,
"cached": false,
"fetchedAt": "2026-07-04T00:00:00.000Z",
"source": "local + Cloudflare DoH"
},
"ok": true
},
"type": "json"
}
},
"routeTemplate": "/email/validate/:email",
"schema": {
"$schema": "https://json-schema.org/draft/2020-12/schema",
"properties": {
"input": {
"additionalProperties": false,
"properties": {
"method": {
"enum": [
"GET"
],
"type": "string"
},
"pathParams": {
"properties": {
"email": {
"description": "Email address to validate.",
"type": "string"
}
},
"required": [
"email"
],
"type": "object"
},
"queryParams": {
"properties": {},
"type": "object"
},
"type": {
"const": "http",
"type": "string"
}
},
"required": [
"type",
"method"
],
"type": "object"
},
"output": {
"properties": {
"example": {
"properties": {
"data": {
"properties": {
"aFallback": {
"description": "True if no MX but the domain has an A record (RFC 5321 fallback).",
"type": "boolean"
},
"deliverable": {
"description": "hasMx OR aFallback. Not a mailbox-existence check.",
"type": "boolean"
},
"domain": {
"description": "Parsed domain part, lowercase, or null if syntax-invalid.",
"type": "string"
},
"email": {
"description": "The address as received.",
"type": "string"
},
"hasMx": {
"description": "Whether the domain publishes MX records.",
"type": "boolean"
},
"mx": {
"description": "MX records sorted by preference: { preference, exchange }.",
"type": "array"
},
"syntaxValid": {
"description": "Whether the address passes syntax validation.",
"type": "boolean"
}
},
"required": [
"email",
"syntaxValid",
"deliverable"
],
"type": "object"
},
"endpoint": {
"description": "Always \"/email/validate/:email\".",
"type": "string"
},
"meta": {
"properties": {
"attribution": {
"description": "Licensing attribution when the source requires it.",
"type": [
"string",
"null"
]
},
"cached": {
"description": "Whether this response was served from cache.",
"type": "boolean"
},
"fetchedAt": {
"description": "ISO 8601 time the data was actually retrieved from the upstream.",
"type": "string"
},
"source": {
"description": "Upstream source: local + Cloudflare DoH.",
"type": "string"
}
},
"required": [
"source",
"cached",
"fetchedAt"
],
"type": "object"
},
"ok": {
"description": "true on success.",
"type": "boolean"
}
},
"required": [
"ok",
"endpoint",
"data",
"meta"
],
"type": "object"
},
"type": {
"type": "string"
}
},
"required": [
"type"
],
"type": "object"
}
},
"required": [
"input"
],
"type": "object"
}
}
}Use it
curl
curl "https://gateway.stride20k.com/email/validate/:email" # -> 402 Payment Required, accepts[] lists how to pay # retry with a PAYMENT-SIGNATURE (or PAYMENT header) once paid
JavaScript
const res = await fetch("https://gateway.stride20k.com/email/validate/:email");
if (res.status === 402) {
const { accepts } = await res.json();
// pay one of accepts[] via an x402 client, then retry with the payment header
}Python
import httpx
res = httpx.get("https://gateway.stride20k.com/email/validate/:email")
if res.status_code == 402:
accepts = res.json()["accepts"]
# pay one of accepts[] via an x402 client, then retry with the payment headerMachine-readable
Everything on this page is also available as clean JSON at /resources/1168.json, and this resource appears in /discovery/resources and /discovery/search.