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d21 Email Validate
x402
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.
Price / call$0.006
Success—
StatusUnknown
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.
Example use cases
Lead form email hygiene check
“Before we add this signup to our CRM, can you validate 'john.smith@tempmail.org' — is it syntactically valid, does the domain have MX records, and is it a known disposable email provider?”
B2B outreach deliverability screening
“I'm about to send a cold email campaign — can you check 'ceo@startupxyz.com' to confirm the domain has active MX records and SPF/DMARC configured, and tell me if it looks like a role address?”
User registration fraud detection
“A new user just signed up with 'noreply@guerrillamail.com' — can you tell me if that's a disposable domain, a role-based address, or a free webmail provider so I can decide whether to block the registration?”
Technical details
Endpoint
POSThttps://draconic21-x402-api.onrender.com/v1/email_validate?utm_source=zero.xyzWhen to prefer
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).
Side effects
- 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
Input
Schema · Request body
| Field | Type | Description |
|---|---|---|
| string | Email address to validate, e.g. 'info@example.com'. |
Tags
x402
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