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New Deep verification for catch-all addresses

Your list is lying to you.

Some mail servers say yes to every address, real or invented. Other verifiers shrug and call it catch-all. We score every one, then send a real email and wait for the bounce.

leads_q4.csv48,210 rowsVerifying
Valid0
Catch-all0
Invalid0
Risky0
Unknown, free0
EmailProviderResult

Catch-all is where the others stop.

Some servers say yes to every address. We do not stop there.

First, a score

Every catch-all gets a score.

The score is a probability, learned from real sends: what delivered, what got a reply, what bounced.

We weigh what we know about the address and its domain, signal by signal.

91%likely to deliver

    Examples. 80% and above is marked safe to send by default.

    Then, proof

    Still not sure? We email it.

    One real email. Delivered means the inbox is real. Bounced means it is not.

    Deep verification, answer within 72 hours
      • $0for unknowns. No answer, no charge.
      • 1,000,000rows per list. Your file back, results added.
      • Re-checkedif a verdict changes later, and we tell you.

      Five verdicts. One of them is free.

      Valid250 2.1.5

      The server took this address and refused a made-up one on the same domain.

      Invalid550 5.1.1

      No such mailbox, no mail server for the domain, or an address that cannot exist.

      Catch-all250 to anything

      The domain accepts every address. Comes with a score, and can be deep verified.

      Risky451 4.7.1

      Still greylisted after three retries, or behind a mail gateway. Can be deep verified.

      Unknown421 / timeout

      Every mail server refused us or timed out. No answer, no charge.

      Switch in an afternoon.

      One address comes back inside five seconds. A list comes back as a file, or on your webhook.

      One call

      curl https://api.verifyinboxes.com/v1/verify \
  -H "Authorization: Bearer $KEY" \
  -d '{"email":"dana@harbor.example"}'

{
  "email": "dana@harbor.example",
  "verdict": "catch_all",
  "score": 0.86,
  "safe_to_send": true,
  "provider": "microsoft",
  "source": "smtp"
}

      Fits what you already run

      InstantlySmartleadWebhooksCSV uploadREST API
      • Single checks jump the queue, ahead of bulk work.
      • Webhooks when a job finishes and when a deep verification comes back.
      • Instantly and Smartlead can report your bounces and replies back, so verdicts keep improving on the domains you mail.
      • Built for B2B lists. A list that is more than 40% consumer addresses is refused.

      A dollar per thousand answers.

      Pay for verdicts, never for shrugs. Unknown results and blank rows are always free.

      Pay as you go

      $0.001 per check

      Every catch-all scored. No commitment.

      Get an API key

      Monthly

      $49 for 100,000 checks

      Half the price per check, with priority on the API.

      Start monthly

      Deep verification

      $0.02 per address

      One real email to each catch-all or risky row, and a yes or no back.

      Get an API key
      Verification
      Deep verification
      Total

      Stop mailing maybes.

      Every address on your list ends as a yes or a no.

      Get an API key