bounceowl
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Block bad signups with one API call.

Typos, throwaway inboxes and made-up addresses cost you onboarding emails and pollute your data. Call BounceOwl at signup and decide what to do with each verdict in your own code.

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The problem

Fake and mistyped signups
Regex catches broken syntax, not mailboxes that don't exist.
Disposable inboxes
Trial abuse and throwaway accounts skew metrics and cost money.
Bounces from transactional email
Sending to dead addresses damages the reputation your product emails depend on.

How it fits your workflow

  1. 1

    Create an API key

    One key per app or environment, revocable at any time.

  2. 2

    Call /v1/verify at signup

    Accept valid, ask the user to fix invalid, and choose your policy for catch-all, unknown and disposable.

  3. 3

    Backfill existing users

    Upload your existing user table with /v1/bulk and download the results.

What helps

  • Email verification API

    Endpoints, limits and pricing in one place.

    API overview

  • API docs

    Request and response examples for every endpoint.

    Read the docs

  • API guide

    curl, Python and Node examples with error handling.

    Read the guide

  • MCP server

    Let your coding assistant check addresses while you work.

    Set up MCP

Check your next list before it costs you a domain.

100 free credits with Google sign-in. Pay as you go after that, and credits never expire.

Start freeSee pricing