Email Check
kycCheck an email address without sending it anything: is the format valid, does the domain accept mail (MX record), is it a throwaway / disposable address (about 9,800 known domains), a free provider like Gmail, or a role address like info@ or sales@. deliverable is true when the domain can receive mail and nothing marks the address as junk. It does not confirm that the individual mailbox exists.
POST /gw/v1/email-check-v1/SLA p95: 2000 ms
Authentication
Pass your key in the X-API-Key header. Use a test_ key against the sandbox and a live_ key in production. Send an optional Idempotency-Key header to safely retry — the same key returns the same response for 24h.
X-API-Key: live_xxxxxxxxxxxx
Request
Endpoint: POST https://apisathi.in/gw/v1/email-check-v1/
The trailing slash is required. /v1/email-check-v1/ works; /v1/email-check-v1 returns 404 Not Found. This applies to every product.
| Field | Type | Required | Constraints |
|---|---|---|---|
| string | required | maxLength: 254 |
Code snippets
curl -X POST https://apisathi.in/gw/v1/email-check-v1/ \
-H "X-API-Key: $API_SATHI_KEY" \
-H "Content-Type: application/json" \
-H "Idempotency-Key: $(uuidgen)" \
-d '{"email":"ravi.kumar@outlook.com"}'Response
| Field | Type | Required | Constraints |
|---|---|---|---|
| string | optional | — | |
| valid_syntax | boolean | optional | — |
| domain | string | optional | — |
| mx_found | boolean | optional | — |
| mx_records | array | optional | — |
| disposable | boolean | optional | — |
| free_provider | boolean | optional | — |
| role_address | boolean | optional | — |
| deliverable | boolean | optional | — |
Sample response
{
"email": "ravi.kumar@outlook.com",
"valid_syntax": true,
"domain": "outlook.com",
"mx_found": true,
"mx_records": [
"outlook-com.olc.protection.outlook.com"
],
"disposable": false,
"free_provider": true,
"role_address": false,
"deliverable": true
}Reading a 400
A schema rejection returns INVALID_REQUEST with a details array naming the exact field. Read it before guessing — it gives you the JSON path and what was wrong with it.
{
"error": {
"code": "INVALID_REQUEST",
"message": "Request body failed schema validation",
"details": [
{ "path": "/callback_url",
"message": "unexpected property 'callback_url' — this endpoint does not accept unknown fields" }
]
}
}Most endpoints reject unknown top-level fields outright, so an extra key you added for your own bookkeeping will fail the call. Enum errors list the accepted values, and a missing required field is named with its full path.
Error codes
| Code | HTTP | When |
|---|---|---|
| INVALID_INPUT | 422 | The request was rejected as invalid — either it failed OUR schema validation (malformed input; not charged), or the upstream source rejected the value you sent. NOTE: an identifier that is well-formed but simply has NO RECORD is no longer an error — it returns 200 with `verified: false` and is charged (see the result-code table below). FIX the input before retrying; retrying the same value will fail again. |
| INVALID_API_KEY | 401 | Missing, malformed, or revoked X-API-Key. |
| OUT_OF_SCOPE | 403 | API key is not scoped for this product. |
| INSUFFICIENT_BALANCE | 402 | Wallet balance is below the per-call sale price. Recharge and retry. |
| RATE_LIMITED | 429 | Per-key RPS or RPM limit exceeded. Back off and retry after the Retry-After header. |
| PRODUCT_DEPRECATED | 410 | This API has been retired and is no longer available. Stop calling it — it will not return. Check the catalog for the current equivalent. |
| ROUTER_NO_VENDOR | 503 | No healthy vendor is currently available for this product. Transient — safe to retry after a short backoff. Not charged. |
| VENDOR_AUTH_FAILED | 502 | Upstream vendor rejected our credentials (our config issue). Not charged. |
| VENDOR_ERROR | 502 | A genuine transient upstream error (the source was briefly unavailable). Safe to RETRY after a short backoff. Not charged. NOTE: this is NOT for bad input — invalid values return 422 INVALID_INPUT, not 502. |
| TIMEOUT | 504 | Upstream vendor did not respond within the SLA window. Safe to retry after a short backoff. Not charged. |
OpenAPI 3.1
Generated from this product's request/response JSON Schemas.
{
"openapi": "3.1.0",
"info": {
"title": "API Sathi — Email Check",
"version": "1.0.0",
"description": "Check an email address without sending it anything: is the format valid, does the domain accept mail (MX record), is it a throwaway / disposable address (about 9,800 known domains), a free provider like Gmail, or a role address like info@ or sales@. deliverable is true when the domain can receive mail and nothing marks the address as junk. It does not confirm that the individual mailbox exists."
},
"servers": [
{
"url": "https://apisathi.in/gw/v1"
}
],
"components": {
"securitySchemes": {
"ApiKeyAuth": {
"type": "apiKey",
"in": "header",
"name": "X-API-Key",
"description": "Your live or test key, e.g. `live_xxxxxxxxxxxx`."
}
}
},
"paths": {
"/email-check-v1": {
"post": {
"operationId": "emailCheckV1",
"tags": [
"kyc"
],
"summary": "Email Check",
"description": "Check an email address without sending it anything: is the format valid, does the domain accept mail (MX record), is it a throwaway / disposable address (about 9,800 known domains), a free provider like Gmail, or a role address like info@ or sales@. deliverable is true when the domain can receive mail and nothing marks the address as junk. It does not confirm that the individual mailbox exists.",
"security": [
{
"ApiKeyAuth": []
}
],
"parameters": [
{
"name": "Idempotency-Key",
"in": "header",
"required": false,
"schema": {
"type": "string"
},
"description": "Optional. Same key returns the same response for 24h."
}
],
"requestBody": {
"required": true,
"content": {
"application/json": {
"schema": {
"type": "object",
"required": [
"email"
],
"properties": {
"email": {
"type": "string",
"maxLength": 254
}
},
"additionalProperties": false
},
"example": {
"email": "ravi.kumar@outlook.com"
}
}
}
},
"responses": {
"200": {
"description": "Successful, normalized response.",
"content": {
"application/json": {
"schema": {
"type": "object",
"properties": {
"email": {
"type": "string"
},
"valid_syntax": {
"type": "boolean"
},
"domain": {
"type": "string"
},
"mx_found": {
"type": "boolean"
},
"mx_records": {
"type": "array"
},
"disposable": {
"type": "boolean"
},
"free_provider": {
"type": "boolean"
},
"role_address": {
"type": "boolean"
},
"deliverable": {
"type": "boolean"
}
}
},
"example": {
"email": "ravi.kumar@outlook.com",
"valid_syntax": true,
"domain": "outlook.com",
"mx_found": true,
"mx_records": [
"outlook-com.olc.protection.outlook.com"
],
"disposable": false,
"free_provider": true,
"role_address": false,
"deliverable": true
}
}
}
},
"401": {
"description": "Missing, malformed, or revoked X-API-Key.",
"content": {
"application/json": {
"schema": {
"type": "object",
"properties": {
"error": {
"type": "object",
"properties": {
"code": {
"type": "string"
},
"message": {
"type": "string"
},
"call_id": {
"type": "string"
}
}
}
}
}
}
}
},
"402": {
"description": "Wallet balance is below the per-call sale price. Recharge and retry.",
"content": {
"application/json": {
"schema": {
"type": "object",
"properties": {
"error": {
"type": "object",
"properties": {
"code": {
"type": "string"
},
"message": {
"type": "string"
},
"call_id": {
"type": "string"
}
}
}
}
}
}
}
},
"403": {
"description": "API key is not scoped for this product.",
"content": {
"application/json": {
"schema": {
"type": "object",
"properties": {
"error": {
"type": "object",
"properties": {
"code": {
"type": "string"
},
"message": {
"type": "string"
},
"call_id": {
"type": "string"
}
}
}
}
}
}
}
},
"410": {
"description": "This API has been retired and is no longer available. Stop calling it — it will not return. Check the catalog for the current equivalent.",
"content": {
"application/json": {
"schema": {
"type": "object",
"properties": {
"error": {
"type": "object",
"properties": {
"code": {
"type": "string"
},
"message": {
"type": "string"
},
"call_id": {
"type": "string"
}
}
}
}
}
}
}
},
"422": {
"description": "The request was rejected as invalid — either it failed OUR schema validation (malformed input; not charged), or the upstream source rejected the value you sent. NOTE: an identifier that is well-formed but simply has NO RECORD is no longer an error — it returns 200 with `verified: false` and is charged (see the result-code table below). FIX the input before retrying; retrying the same value will fail again.",
"content": {
"application/json": {
"schema": {
"type": "object",
"properties": {
"error": {
"type": "object",
"properties": {
"code": {
"type": "string"
},
"message": {
"type": "string"
},
"call_id": {
"type": "string"
}
}
}
}
}
}
}
},
"429": {
"description": "Per-key RPS or RPM limit exceeded. Back off and retry after the Retry-After header.",
"content": {
"application/json": {
"schema": {
"type": "object",
"properties": {
"error": {
"type": "object",
"properties": {
"code": {
"type": "string"
},
"message": {
"type": "string"
},
"call_id": {
"type": "string"
}
}
}
}
}
}
}
},
"502": {
"description": "Upstream vendor rejected our credentials (our config issue). Not charged.",
"content": {
"application/json": {
"schema": {
"type": "object",
"properties": {
"error": {
"type": "object",
"properties": {
"code": {
"type": "string"
},
"message": {
"type": "string"
},
"call_id": {
"type": "string"
}
}
}
}
}
}
}
},
"503": {
"description": "No healthy vendor is currently available for this product. Transient — safe to retry after a short backoff. Not charged.",
"content": {
"application/json": {
"schema": {
"type": "object",
"properties": {
"error": {
"type": "object",
"properties": {
"code": {
"type": "string"
},
"message": {
"type": "string"
},
"call_id": {
"type": "string"
}
}
}
}
}
}
}
},
"504": {
"description": "Upstream vendor did not respond within the SLA window. Safe to retry after a short backoff. Not charged.",
"content": {
"application/json": {
"schema": {
"type": "object",
"properties": {
"error": {
"type": "object",
"properties": {
"code": {
"type": "string"
},
"message": {
"type": "string"
},
"call_id": {
"type": "string"
}
}
}
}
}
}
}
}
}
}
}
}
}