# x-402 Email Address Verifier

> x-402 Email Address Verifier is a paid API for AI agents from api.x-402.online, paid per call via x402, $0.005/call, status unknown (last checked 2026-10-02).

Validates an email address through five DNS-based checks (syntax, MX, SPF, DMARC, disposable domain, role address) and returns a deliverability rating of NO, RISKY, or LIKELY — without sending any message or opening an SMTP session.

## Facts

- Endpoint: GET https://api.x-402.online/v1/email/verify?utm_source=zero.xyz
- Price: $0.005/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-02
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/x-402-email-address-verifier-03470a8c
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_ha07sRgAG0avaKj4sAVmQ

Status and success rate cover calls made through Zero and Zero's own probes. Third-party monitors may report differently.

## How to call it through Zero

Zero handles the 402 payment challenge and records the run. With the Zero CLI installed (`npm i -g @zeroxyz/cli`):

```sh
zero fetch --capability x-402-email-address-verifier-03470a8c
```

Example prompt: Before I add john.doe@example.com to my campaign list, can you run a full email verification on it — check the syntax, MX records, SPF, DMARC, whether it's a disposable domain, and whether it's a role address — and tell me if it's deliverable?

## When to prefer this

Choose this endpoint when you need a fast, privacy-safe email pre-validation that doesn't send any message or require SMTP access. Ideal for lead qualification, sign-up form gating, CRM hygiene, and mailing list scrubbing where you want DNS-level confidence (syntax + MX + SPF + DMARC + disposable + role checks) without touching the recipient's inbox. Prefer it over full SMTP verification when avoiding false deliveries or GDPR-sensitive probe messages is important.

## Known failure modes

- Invalid or malformed email input returns a syntax error without DNS checks
- DNS lookup timeout may prevent MX/SPF/DMARC results from being returned
- Private or internal domains may return no MX/SPF/DMARC records even for valid addresses
- Payment failure (402) if USDC balance is insufficient
- Rate limiting if too many requests are made in quick succession

## How this service works

Check whether an email address is well-formed and its domain can receive mail, before you send. Five DNS checks on an email address, no message sent: syntax, MX presence and hosts, SPF record, DMARC policy, disposable domain, role address. Returns deliverable as NO, RISKY or LIKELY. It does not open an SMTP session and says so: mailbox existence is explicitly not c…

## Output

Returns a deliverability verdict of NO, RISKY, or LIKELY along with individual check results covering: email syntax validity, MX record presence and hostnames, SPF record content, DMARC policy, whether the domain is a known disposable provider, and whether the local part is a role address (e.g. info@, admin@). Mailbox existence is explicitly not checked — no SMTP session is opened.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "$schema": "https://json-schema.org/draft/2020-12/schema",
 "required": [
  "input"
 ],
 "properties": {
  "input": {
   "type": "object",
   "required": [
    "type",
    "method"
   ],
   "properties": {
    "type": {
     "type": "string",
     "const": "http"
    },
    "method": {
     "enum": [
      "GET"
     ],
     "type": "string"
    },
    "queryParams": {
     "type": "object",
     "properties": {}
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object"
    }
   }
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/x-402-email-address-verifier-03470a8c/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from api.x-402.online](https://www.zero.xyz/host/api.x-402.online/llms.txt)