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Email Validation API

Validate emails inside outbound workflows with clear result semantics and credit behavior.

Use the GTMAPIs Email Validation API to validate single emails, synchronous batches, and async CSV jobs from automation-first outbound systems.

Public endpoints

/v1/validate/v1/validate/bulk/v1/validate/batch/v1/csv/prepare-upload/v1/csv/start-processing/v1/csv/jobs

Auth header: X-API-Key

Create an API keyRead API docs

Use this API when

  • You need single-email validation behind a public API.
  • You need synchronous bulk validation for small batches.
  • You need async CSV validation jobs with signed download handoff.
  • You need canonical statuses such as valid, valid_role_based, risky, invalid, and unknown.

Do not use it when

  • You need a manual dashboard-only list cleanup workflow.
  • You need a guarantee of inbox placement, reply rate, or meeting conversion.
  • You need dormant future-product workflows that are outside the public API catalog.
bash request
curl -X POST https://api.gtmapis.com/v1/validate \
+  -H 'Content-Type: application/json' \
+  -H 'X-API-Key: gtm_test_1234567890abcdef1234567890abcdef' \
+  -d '{"email":"alex@example.com"}'
json response
{
  "email": "alex@example.com",
  "status": "valid",
  "is_role_based": false,
  "is_catchall": false,
  "b2b_outbound_quality": "high",
  "credits": {
    "reserved": 1,
    "consumed": 1,
    "refunded": 0
  }
}

Result semantics

  • valid means the result passed validation checks and can be high-value when it is not role-based, catch-all, risky, invalid, or unknown.
  • valid_role_based is a first-class status for role-based addresses.
  • risky covers catch-all and other results that should not be treated as deterministic mailbox verification.
  • invalid is a definitive failed result that is never high-value and should be suppressed from sends.
  • unknown is non-chargeable when uncertainty comes from temporary DNS, SMTP, provider, or transport uncertainty.

Credit behavior

  • Standard validation charges one credit for a High-Value Validation.
  • Role-based, catch-all, invalid, risky, and unknown outcomes do not consume standard validation credits by default.
  • Bulk and CSV summaries expose reserved, consumed, and refunded credit fields.

Errors and failures

  • Authentication errors should be resolved with a valid API key sent through X-API-Key.
  • Scope errors should be resolved by rotating to a key with the required email validation scope.
  • Transport failures are not validation results and should be retried rather than treated as unknown outcomes.

Common questions

What authentication header does the API use?

Public API requests use the X-API-Key header.

Does every validation consume a credit?

No. Standard validation credit consumption is tied to High-Value Validation outcomes.

Are future acquisition or enrichment products part of this API page?

No. This page covers the available Email Validation API only.