Email Realtime Check

POST/v1/realtime/check/email

Synchronously check one email address against one to ten realtime email products. The engine, the billing contract and the response shape are identical to the phone endpoint; only the series and the identifier format differ.

Parameters

Field	Type	Required	Description
identifier	string	Yes	One email address, for example user@example.com.
country	string	No	Must be omitted for email. Sending a country code with an email product is rejected.
product_ids	array<int>	Yes	An array of 1 to 10 realtime email product IDs.

Country must be empty

Email has no country dimension. country is optional on the phone endpoint but is not accepted here — a request that carries one fails validation before anything is submitted or charged.

Idempotency required

Idempotency-Key is required on every call. Retrying the same request with the same key does not charge twice; changing the payload returns 409. See Idempotency & retries.

Choosing the products

Email and phone products are different series and cannot be combined in one request. Read the id of an entry whose mode is realtime and whose series is email off Realtime products, which is backed by GET /v1/products. Passing a slug never works here, and a phone product ID in an email call is rejected as an unmatchable series.

Response Example

{
  "request_id": "b7d2a1c4-9f3e-4a1b-8c5d-2e6f7a8b9c0d",
  "identifier": "user@example.com",
  "series": "email",
  "status": "succeeded",
  "request_status": "completed",
  "replayed": false,
  "total_reserved": 0.004000,
  "total_charged": 0.004000,
  "total_refunded": 0.000000,
  "charged_amount": 0.004000,
  "refunded_amount": 0.000000,
  "results": [
    {
      "product_id": 49,
      "product": "insemailvalid-rt",
      "result": "valid",
      "cached": false,
      "billing_status": "charged",
      "charged_amount": 0.002000,
      "refunded_amount": 0.000000,
      "checked_at": "2026-09-13T10:00:00Z",
      "error_code": null
    }
  ]
}

The product_id values above are examples — confirm the current email product IDs on Realtime products before you send a real request. request_id is a UUID, and cached lives inside each result, not at the top level.

The only differences from a phone response are series: "email" and the identifier format. Every other field — including the billing and results entries — is documented field-by-field under Response fields.

cURL Example

curl -X POST "https://api.zelnum.com/api/v1/realtime/check/email" \
  -H "X-API-Key: YOUR_KEY_HERE" \
  -H "Idempotency-Key: UNIQUE_REQUEST_ID" \
  -H "Content-Type: application/json" \
  -d '{"identifier":"user@example.com","product_ids":[49]}'

Errors specific to email

HTTP	code	Meaning / action
400	invalid_realtime_request	The address is malformed, country was sent, the IDs belong to another series, or no ID was supplied. Nothing is submitted and nothing is charged.
400	idempotency_key_required	Idempotency-Key header missing.
402	insufficient_balance	Balance does not cover the reservation; no item starts.
409	request_in_progress / idempotency_conflict	Same key, still running, or same key with a different payload.

The remaining status codes — 401, 403, 429, 503, 500 — behave exactly as documented on the phone endpoint.