WillItInbox

Solution

Email validation API for product and growth workflows.

Validate email addresses through API, batch, and bulk workflows with evidence for SMTP, catch-all, disposable, role-based, typo, MX, and confidence signals.

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Validation for more than forms

Email validation is useful anywhere a bad address creates cost: signup, lead capture, CSV imports, outbound campaigns, support workflows, and data enrichment.

  • Single validation for product forms and admin tools.
  • Batch validation for small enrichment jobs.
  • Bulk CSV upload for larger imports and list hygiene sweeps.

API response philosophy

The API returns evidence and confidence instead of pretending every address can be proven safe. SMTP behavior varies by provider, so inconclusive results stay visible.

SignalWhy it mattersHow to use it
SMTPMailbox-level evidence when the provider allows it.Trust confirmed failures; treat blocks carefully.
Catch-allRandom mailboxes appear accepted.Segment because acceptance does not prove user existence.
DisposableTemporary inbox provider.Suppress for product quality or fraud-sensitive flows.
RoleShared addresses like sales@ or info@.Allow or segment based on campaign intent.