bounceowl
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Verify emails from your own code.

One POST returns the verdict and the evidence in the same response. Use it at signup, before a CRM import, or inside your own tools. Same credits and free unknowns as the app.

Get an API keyRead the API docs

100 free credits with Google sign-in. Unknown results are always free.

BounceOwl history showing checks from the app, lists, the API and MCP. Sample data.

How it works

  1. 1

    Create a key

    Sign in, open API & MCP and create a key. It's shown once; revoke it any time and it stops working right away.

  2. 2

    Call /v1/verify

    Send an email address and get the verdict, reason, mail server, provider and flags back in JSON.

  3. 3

    Handle the answer

    Accept valid, block invalid, and decide your own policy for catch-all and unknown. A 402 tells you when credits run out.

What you get

Synchronous results
The answer comes back in the same request. Set your client timeout to at least 150 seconds for slow mail servers.
Lists and catch-all too
Upload files with /v1/bulk, start them, poll status and download CSV results. Run /v1/catchall on catch-all results.
Predictable billing
1 credit per real answer, unknown and recently checked addresses free. GET /v1/pricing returns current prices.
Sensible limits
300 verify calls per minute per key by default. Errors explain what went wrong and how much credit is needed.

One request, one answer

Send the address, get the verdict with its evidence. Every response field is documented in the API docs.

curl https://api.bounceowl.com/v1/verify \
  -H "Authorization: Bearer $BOUNCEOWL_KEY" \
  -H "Content-Type: application/json" \
  -d '{"email": "maya.chen@lumenforge.io"}'

{
  "verdict": "valid",
  "mailbox": "accepts_mail",
  "mail_server": "aspmx.l.google.com",
  "provider": "google_workspace",
  "catch_all": false,
  "role": false,
  "charged": 1
}

Questions

Is there a sandbox?

New accounts get 100 free credits, and addresses on domains with no mail server (like example.com) are always free, so you can test safely.

What happens when credits run out?

The API returns 402 with how many credits the request needs and your balance. Nothing is checked or charged.

Can AI assistants use it?

Yes. The same account works with the BounceOwl MCP server for Claude Code, Codex, Cursor and others.

How fast is it?

Most checks answer in a few seconds. Some mail servers are slow, so allow up to two minutes.

Related

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