# d21 Email Validate

> d21 Email Validate is a paid API for AI agents from draconic21-x402-api.onrender.com, paid per call via x402, $0.006/call, status unknown (last checked 2026-10-12).

Validates an email address for syntax, live DNS-based deliverability (MX/A-fallback), disposable domain detection, role-address detection, free webmail provider detection, and SPF/DMARC presence — all without any third-party validation vendor or SMTP probing.

## Facts

- Endpoint: POST https://draconic21-x402-api.onrender.com/v1/email_validate?utm_source=zero.xyz
- Price: $0.006/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-12
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/d21-email-validate-6fdb6a10
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_a79BMFiXZxH5NdfQEIobU

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 d21-email-validate-6fdb6a10 -d '<json body>'
```

Example prompt: Can you check whether 'info@acmecorp.io' is a real, deliverable email — flag if it's disposable, a role address, or a free webmail domain, and tell me if the domain has SPF and DMARC set up?

## When to prefer this

Choose this endpoint when you need fast, self-contained email validation that covers syntax, DNS deliverability, disposable/role/webmail classification, and SPF/DMARC — all without relying on a third-party validation vendor or opening SMTP connections. Prefer it over SMTP-probing services when you want privacy-safe validation that won't trigger remote mail servers. Ideal for pre-send list hygiene, registration fraud screening, or lead qualification pipelines where you want deterministic, auditable DNS-based signals at low cost ($0.006/call).

## Known failure modes

- Malformed or missing email field returns a validation/syntax error
- DNS resolution timeout if the domain's DNS is slow or unresponsive
- Domain not found in DNS returns a non-deliverable status but is not an API error
- Does not confirm whether a specific inbox exists — only domain-level deliverability
- Disposable domain list is static and may not include very new throwaway services
- Free webmail and disposable lists depend on freshness of self-maintained data

## How this service works

Email Validate ($0.006): syntax + live MX/A-fallback deliverability + disposable-domain + role-address + free-webmail-provider + SPF/DMARC, with no third-party validation vendor at all -- syntax is RFC 5321/5322 grammar, MX/A/SPF/DMARC are live DNS via this server's own resolver (the same protocol-level sourcing as domain_intel), and disposable-domain detection is a static self-maintained list. Never opens an SMTP connection to the mailbox or confirms one specific inbox exists. Body { email }…

## Output

Returns structured results covering: RFC 5321/5322 syntax validity, live DNS MX/A-fallback deliverability status, whether the domain is on a self-maintained disposable-domain blocklist, whether the local part is a role address (e.g. info@, support@), whether the domain is a known free webmail provider, and whether the domain has SPF and DMARC DNS records — all resolved via the server's own DNS resolver with no third-party vendor and no SMTP probing.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "email": {
   "type": "string",
   "description": "Email address to validate, e.g. 'info@example.com'."
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/d21-email-validate-6fdb6a10/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from draconic21-x402-api.onrender.com](https://www.zero.xyz/host/draconic21-x402-api.onrender.com/llms.txt)