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FreeTier Agent API — Email Domain Verification
x402
FreeTier Agent API — Email Domain Verification is a paid API for AI agents from freetier-agent-api.pages.dev, paid per call via x402, $0.001/call, status unknown (last checked 2026-10-18).
Checks an email address for syntax validity, MX records, disposable domain status, free-mail provider status, and overall deliverability risk
Price / call$0.001
Success—
StatusUnknown
How this service works
Pay-per-call data API for AI agents: AI model prices and cost calculator, 4,259 MCP servers, email domain checks, text-to-JSON extraction, country/holiday/currency lookup, page and link checks, page-to-markdown, 2,230 verified APIs. x402, USDC on Base, no signup. Sources cited in every response.
Output
A JSON object containing: the normalized email and domain, a boolean for syntax validity, a boolean for MX record presence, a boolean for disposable domain, a boolean for free-mail provider, a boolean for role address (e.g. info@, support@), a verdict string (e.g. 'risky', 'safe'), and an array of human-readable reasons explaining the verdict.
Example use cases
Sign-up fraud screening
“Before we create an account for this new user, can you verify that their email address user123@mailnull.com is legitimate — check if it's disposable, has valid MX records, and isn't a throwaway domain?”
Mailing list quality check
“I have a lead who gave us the email contact@somebusiness.co — can you tell me if that domain actually has mail servers set up, whether it's a free or role-based address, and whether it's safe to add to our campaign list?”
Detecting free-mail vs business email
“Can you check whether the email john.smith@gmail.com is from a free mail provider and whether it passes syntax and MX validation, so I can decide whether to route them as a consumer or business lead?”
Technical details
Endpoint
GEThttps://freetier-agent-api.pages.dev/api/email-verify?utm_source=zero.xyzWhen to prefer
Choose this endpoint when you need a lightweight, pay-per-call email risk assessment without a subscription — particularly useful for agents doing real-time sign-up validation, lead qualification, or mailing list hygiene. It combines syntax, MX, disposable, free-mail, and role-address checks in a single call, with no API key or account required, billed at $0.005 USDC via x402 on Base.
Side effects
- Missing or malformed email query parameter returns an error
- Email with valid syntax but unresolvable domain returns has_mx:false and risky verdict
- Network or DNS lookup timeout may cause delayed or failed response
- Newly registered domains may not yet have MX records leading to false risky verdict
- Catch-all mail servers may cause MX checks to pass even for non-existent mailboxes
Input
Schema · Request body
| Field | Type | Description |
|---|---|---|
| inputrequired | object | |
| output | object |
Output
Schema · Response
{
"type": "json",
"example": {
"role": false,
"email": "jane.doe@example.com",
"domain": "example.com",
"has_mx": false,
"reasons": [
"no MX records"
],
"verdict": "risky",
"free_mail": false,
"syntax_ok": true,
"disposable": false
}
}Tags
x402
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