Email Verification API
Single, Bulk, and Catch-All Resolution

Add email verification with catch-all resolution to any application, pipeline, or workflow. One API key, four endpoints, confirmed results only.

Quick start

One Line to Verify an Email

Generate an API key from your dashboard, pass it as a Bearer token, and start verifying.

curl -X POST https://api.filtrat.io/v1/verify/email \
  -H "Authorization: Bearer ak_your_key" \
  -H "Content-Type: application/json" \
  -d '{"email": "andrew.cooper@snowplow.io"}'

Response

{
  "email": "andrew.cooper@snowplow.io",
  "status": "verified",
  "confidence": 98,
  "syntax_valid": true,
  "disposable": false,
  "role_account": false,
  "domain_intelligence": {
    "mx_provider": "Google Workspace",
    "gateway": null,
    "real_provider": "Google Workspace",
    "catch_all": false,
    "spf": "v=spf1 include:_spf.google.com ~all",
    "dmarc": "v=DMARC1; p=reject"
  },
  "diagnosis": null,
  "catchall_resolved": null,
  "is_cached": false,
  "credits_used": 0.5,
  "credits_remaining": 9847.5
}

Endpoints

What the Email Verification API Covers

Single email verification

POST /v1/verify/email

Verify one address per request. Add resolve_catchall: true to resolve catch-all domains in the same call.

0.5 cr per result

Bulk email verification

POST /v1/bulk/jobs

Upload a CSV or submit a JSON array. Poll for status, retrieve results filtered by type, export as CSV.

0.5 cr per result

Catch-all resolution

POST /v1/bulk/jobs/{id}/resolve-catchalls

Resolve catch-all addresses after a bulk job or inline with single verification. Unresolvable costs nothing.

3 cr per confirmed

Email pattern lookup

POST /v1/domain-intelligence/lookup

Returns naming conventions with usage percentages. One lookup covers every address on that domain.

7 cr per domain

Domain inspection

POST /v1/domain-intelligence/inspect

Always free. MX provider, catch-all status, SPF, DMARC, gateway detection.

Billing & API keys

GET /v1/billing/status

GET /v1/api-keys

POST /v1/api-keys

Credit balances, subscription status, key management.

Use cases

Common Integration Patterns

Lead gen pipeline

New lead enters CRM → API verifies email → confirmed = add to sequence, catch-all = resolve, bounce = remove.

Signup form validation

User submits email → API verifies in real time → block disposable and invalid before they enter your database.

Bulk list cleaning

Upload CSV from Apollo, Clay, or LinkedIn → bulk verify → download confirmed deliverables → import to Instantly, Woodpecker, or Lemlist.

Clay waterfall replacement

Replace expensive Clay verification credits with a single filtrat API call. One HTTP node, same result, fraction of the cost.

Pricing

API Verification Pricing — Same as Dashboard

Credit costs

Confirmed deliverable0.5 credits

Confirmed bounce0.5 credits

Catch-all resolution3 credits

Pattern lookup7 credits / domain

Domain inspectfree

Catch-all detectionfree

Uncertain / riskyfree

Cached results (180 days)free

Rate limits

Single verify30 req/min

Bulk job creation5 req/min

Job polling60 req/min

Pattern lookup10 req/min

Domain inspect20 req/min

CSV export10 req/min

Credits are deducted per result, not per request.

See full plan pricing

Ecosystem

Works With Your Stack

REST API with JSON responses — works with anything that makes HTTP requests. Pre-built n8n templates ready to use. MCP server coming soon.

n8n

Clay

Instantly

Woodpecker

Lemlist

HubSpot

Zapier

Make

Full API documentation

Every endpoint, every parameter, every response field.

View API docs

200 free credits. No card.

Email Verification APISingle, Bulk, and Catch-All Resolution