# Email Verification API

Real-time email verification for AI agents, with a quality score.

| Field | Value |
| --- | --- |
| Provider | APIStead Labs |
| Category | Verification |
| Networks | Base |
| Price | $0.001 per call |
| Base URL | https://apistead.qd.je/api/v1 |
| Verification | verified (1/1 routes) |
| Last verified | 2026-11-13T13:52:26.507Z |
| Receipt | https://basescan.org/tx/0x921a420d189953841232d7d6771f1352b34a5bec27ce76c4701aa6b958755a9e |
| JSON | https://x402.apistead.qd.je/api/apis/email-verification-api |
| Markdown | https://x402.apistead.qd.je/api/apis/email-verification-api/md |
| MCP | https://apistead.qd.je/mcp |
| API reference | https://x402.apistead.qd.je/api |
| OpenAPI | https://x402.apistead.qd.je/openapi.json |

## For AI agents

Check email syntax, domain and MX records before an agent sends a signup, invoice or outreach message.

## Scope

Domain-level check only. Does not prove the mailbox exists, send a test message or perform SMTP probing. Disposable and role lists are curated samples, not a licensed feed.

## Agent intents

- validate an email address
- check if an email domain can receive mail
- screen an email before signup
- detect a disposable email domain

Real-time email verification for AI agents. Before an agent sends a signup, invoice or outreach email, it should know whether the domain can receive mail. This API validates syntax, normalises the address, resolves MX records, detects null MX and implicit MX, flags disposable and role accounts, and suggests common domain typos.

The response includes a `verdict` (`deliverable`, `risky`, `undeliverable`, `unknown`), a `reason` code and a quality score from 0 to 100. It does not perform an SMTP handshake or prove that a mailbox exists, so it is safe to run at volume.

## Endpoints

### POST /email/verify

Verify email syntax, domain and MX records.

- URL: https://apistead.qd.je/api/v1/email/verify
- Price: $0.001 USDC per call
- Pay to: 0x2E9804240E493DD8daeBa4F341a5086b92cde235
- Verified: yes
- Last checked: 2026-11-14T03:35:09.709Z
- Latency: 5 ms
- Uptime (30d): 87.88%

Example request:

```http
POST https://apistead.qd.je/api/v1/email/verify
{"email":"hello@example.com"}
```

Example response:

```json
{
  "mx": [],
  "note": "Domain-level check only. Mailbox existence is not confirmed and no message is sent.",
  "email": "person@example.com",
  "checks": [
    {
      "name": "syntax",
      "detail": "Email syntax is valid.",
      "status": "pass"
    },
    {
      "name": "mx",
      "detail": "No MX record was found.",
      "status": "fail"
    }
  ],
  "domain": "example.com",
  "reason": "no_mx",
  "null_mx": false,
  "preview": true,
  "verdict": "undeliverable",
  "checked_at": "2026-11-10T00:00:00Z",
  "confidence": 0,
  "disposable": false,
  "suggestion": null,
  "implicit_mx": false,
  "accepts_mail": false,
  "role_account": false,
  "free_provider": false,
  "mailbox_checked": false,
  "normalized_email": "person@example.com"
}
```

## Payment

Every paid route uses x402 over HTTP. Call the route without payment to receive a 402 challenge, then pay the quoted USDC amount and retry. The 402 challenge is the authoritative source for price, asset, network and pay-to address. Reading this record and the discovery API is free.

- Protocol: x402 v2
- Asset: USDC
- Networks: Base
- Price: $0.001 per call

## Verification

- State: verified
- Routes verified: 1/1
- Last verified: 2026-11-13T13:52:26.507Z
- Receipt: https://basescan.org/tx/0x921a420d189953841232d7d6771f1352b34a5bec27ce76c4701aa6b958755a9e

## FAQ

### Does this API confirm that a mailbox exists?

No. It verifies the domain and its mail route. It does not use SMTP, does not send a message, and returns mailbox_checked: false. A deliverable verdict means the domain can accept mail, not that the specific inbox exists.

### What does the quality score mean?

The quality score from 0 to 100 combines syntax, MX, implicit MX, disposable-domain, role-account and typo signals. It is a confidence indicator, not a guarantee of delivery.

### Is this a real-time API?

Yes. The API performs the domain and MX checks during the request and returns a structured result in one call. It does not run a slow SMTP mailbox probe.

### Does it send email or use SMTP?

No. The API uses DNS only. It does not connect to SMTP port 25, does not send mail and does not store the email address.

### How much does a call cost and how do agents pay?

A call costs $0.001 USDC on Base. The agent reads the x402 402 challenge, pays the provider wallet directly and retries. There is no API key or subscription.

### What is a null MX record?

A null MX record tells senders that the domain does not accept email. The API marks that domain as undeliverable instead of treating the missing mailbox as a temporary failure.

## Agent links

- JSON: https://x402.apistead.qd.je/api/apis/email-verification-api
- Markdown: https://x402.apistead.qd.je/api/apis/email-verification-api/md
- Routes: https://x402.apistead.qd.je/agent/routes?id=email-verification-api
- Receipts: https://x402.apistead.qd.je/agent/receipts?id=email-verification-api
- API reference: https://x402.apistead.qd.je/api
- MCP guide: https://x402.apistead.qd.je/mcp-docs
- Agent skill: https://x402.apistead.qd.je/skill
- OpenAPI: https://x402.apistead.qd.je/openapi.json
- MCP: https://apistead.qd.je/mcp
- Docs: https://apistead.qd.je/api


## Changelog

### 1.0.0 - Initial verified release

The route is live and settlement-verified on Base mainnet. Health checks, public receipts and agent-readable records are available.

release · 2026-11-11 · APIStead Labs