Email validation API

Verify a single email address over the API with SMTP validation and global verification credits—without creating a contact.

Use this endpoint when you need a deliverability check in Clay, Make, Zapier, or your own code without adding a row to SuperSend contacts.

One credit call returns both the SMTP deliverability verdict and the full email intelligence layer (risk score, provider detection, historical signals). This mirrors the in-app experience, where a single validation credit unlocks both data sets.

ℹ️

Related features

- Contacts: Create contact with validate_emails: true verifies an address when you add someone to a campaign (same credit pool).

Intelligence data: Risk scoring, provider signals, and network history are returned only from this verification endpoint (or from validation tied to contacts/CSV)—not as a separate public API you can call without consuming verification credits.

Endpoint

Method	Path
`POST`	`/v2/email-validation/verify`

Base URL: https://api.supersend.io/v2 (same as all V2 endpoints).

Authentication

Use your API key like every other V2 call:

bash

-H "Authorization: Bearer YOUR_API_KEY"

You can also use X-API-Key. The key must belong to a user with an organization (credits are charged to the org).

Request body

Field	Type	Required	Description
`email`	string	Yes	Email address to verify (normalized to lowercase).
`TeamId`	UUID	No	If set, credit usage is attributed to this team in reporting. You must have access to the team. Omit for org-level-only attribution.

json

{
  "email": "prospect@example.com",
  "TeamId": "550e8400-e29b-41d4-a716-446655440000"
}

Credits

Each successful verification consumes global email verification credits (the same pool as CSV validation and validate_emails on create contact).

If the org does not have enough credits, the API returns 402 with requiredCredits and availableCredits in the error payload.

Credits are recorded after the validator returns a complete result.

Success response

Standard V2 shape: success, data, request_id.

Deliverability fields

Field	Description
`email`	Normalized email that was checked.
`valid`	Whether the SMTP probe treated the mailbox as deliverable.
`validators`	Raw breakdown from the validator (e.g. SMTP probe details).
`credits_used`	Credits debited for this call (often `1`; depends on org credit cost settings).

Intelligence fields (included at no extra cost)

Field	Description
`email_hash`	SHA-256 hash of the normalized address.
`domain`	Domain portion of the address.
`is_role_based`	`true` if the local part is a role alias (`info@`, `support@`, etc.).
`is_abuse_email`	`true` if the address is flagged for abuse or spam.
`is_free_provider`	`true` if the domain is a free consumer email provider.
`is_disallowed`	`true` if the address is on the global disallow list (disposable, etc.).
`validity_score`	Aggregate score 0–100 (100 = cleanest).
`risk_level`	`LOW`, `MEDIUM`, `HIGH`, or `CRITICAL`.
`confidence`	How much historical data backs the score: `NONE`, `LOW`, `MEDIUM`, `HIGH`.
`email_provider`	Detected ESP or mailbox provider (e.g. `Google Workspace`). `null` if unknown.
`email_security_service`	Detected gateway/SEG (e.g. `Proofpoint`). `null` if unknown.
`bounce_type_breakdown`	Historical breakdown of observed bounce types across the SuperSend network.
`total_sends`	Total sends seen for this address across the network.
`hard_bounce_count`	Hard bounces observed across the network.
`reply_count`	Replies observed across the network.
`has_historical_data`	`true` if this address has network-level delivery history.

Example

json

{ "success": true, "data": { "email": "prospect@example.com", "valid": true, "validators": {}, "credits_used": 1, "email_hash": "a1b2c3...", "domain": "example.com", "is_role_based": false, "is_abuse_email": false, "is_free_provider": false, "is_disallowed": false,

"validity_score": 82, "risk_level": "LOW", "confidence": "MEDIUM", "email_provider": "Google Workspace", "email_security_service": null, "bounce_type_breakdown": null, "total_sends": 14, "hard_bounce_count": 0, "reply_count": 3, "has_historical_data": true }, "request_id": "req_..." }

Errors

HTTP	When
401	Missing or invalid API key / no org context.
402	Insufficient email verification credits.
403	`TeamId` provided but you do not have access to that team.
400	Invalid JSON body or missing `email`.
503	Validator did not return a usable result (no credit charge for that failure path).

See Error handling for the standard error JSON shape.

Example: cURL

bash

curl -sS -X POST 'https://api.supersend.io/v2/email-validation/verify' \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d 700 dark:text-green-400">'{"email":"prospect@example.com"}'

OpenAPI and Explorer

Human-readable spec: This page; the V2 API overview lists the endpoint in the table.

Machine-readable spec: GET /v2/openapi.yaml and GET /v2/openapi.json (see V2 API overview).

Try it: API Explorer → tag Email validation → Verify email (SMTP).