# x402-tollbooth Email Verifier

> x402-tollbooth Email Verifier is a paid API for AI agents from x402-tollbooth.onrender.com, paid per call via x402, $0.005/call, status unknown (last checked 2026-10-11).

Validates up to 25 email addresses per call by checking syntax, domain MX/A records, disposable-domain status, and role-account flags — without SMTP mailbox probing.

## Facts

- Endpoint: POST https://x402-tollbooth.onrender.com/api/verify?utm_source=zero.xyz
- Price: $0.005/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-11
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/x402-tollbooth-email-verifier-f8327617
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_DAxZBYG1OJCyCXZoIQmaf

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 x402-tollbooth-email-verifier-f8327617 -d '<json body>'
```

Example prompt: Can you check whether these email addresses are valid and flag any that are disposable or role-based: alice@example.com, info@tempmail.org, support@acme.io?

## When to prefer this

Choose this endpoint when you need fast, lightweight bulk email validation (syntax + domain-level checks) without triggering SMTP connections or risking blacklisting. Ideal for pre-send list hygiene, fraud detection at signup, and CRM import validation where mailbox-level SMTP probing is unnecessary or prohibited. Best for batches up to 25 addresses per call at very low cost per check.

## Known failure modes

- More than 25 emails submitted in a single call — batch exceeds the per-call limit
- Malformed JSON body or missing 'emails' array field — returns 400-level error
- Payment not attached or insufficient — x402 payment required error
- Domain DNS lookup timeout — may result in inconclusive MX/A record status
- Service cold-start latency on Render free tier — initial request may be slow

## How this service works

Check whether email addresses are real and safe to send to. Verifies up to 25 addresses per call: syntax, domain MX/A record (including null-MX), disposable-domain, role-account, free-provider and typo checks. Does not perform SMTP/mailbox verification.

## Output

Returns per-address validation results covering: syntax check pass/fail, domain MX record presence, domain A record presence, whether the domain is a known disposable/temporary email provider, and whether the address is a role account (e.g. admin@, info@, support@). Does not confirm whether a specific mailbox exists on the server.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "emails": {
   "type": "array",
   "items": {
    "type": "string"
   },
   "description": "Array of email address strings, max 25 per call."
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/x402-tollbooth-email-verifier-f8327617/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from x402-tollbooth.onrender.com](https://www.zero.xyz/host/x402-tollbooth.onrender.com/llms.txt)