API reference / Email verification

Verify email addresses

Written and maintained by The ProspectAPIs team

POST/v1/email/verify

POST /v1/email/verify is the ProspectAPIs operation verifyEmails, in the Email verification group of the REST API. Check 1 to 25 email addresses for deliverability. Each result has a status of valid, invalid, catch-all or unknown. A valid or invalid result is charged at the verification price; catch-all and unknown results are free (the charged and free statuses are listed in GET /pricing under email_verification). A paced or timed-out check returns unknown, free. When the balance covers only some addresses, the call verifies as many as it can pay for, the rest come back unknown with reason not_checked_insufficient_credits, free, and the response carries X-Result-Capped: balance. A balance that covers none answers 402. Cost: $0.004 per valid or invalid result; catch-all and unknown are free. Send your API key as a Bearer token in the Authorization header.

How this fits with the rest of the email verification API, with worked examples, is in the email verification guide.

Parameters

Request body

JSON (EmailVerifyRequest).

{
  "emails": [
    "jane@acme.com",
    "sales@example.com"
  ]
}

Responses

Every error answers with the same JSON body, an error string and sometimes a code; the errors page lists each status and when it happens. A per-key 429 carries Retry-After; see rate limits.

200 response fields

One result per address. The body is a EmailVerifyResponse.

Code samples

Each sample sends the same request. Set PROSPECTAPIS_KEY in your environment first. Values come from the spec's examples; replace them with your own.

curl -X POST https://api.prospectapis.com/v1/email/verify \
  -H "Authorization: Bearer $PROSPECTAPIS_KEY" \
  -H "Content-Type: application/json" \
  -d '{ "emails": [ "jane@acme.com", "sales@example.com" ] }'

const res = await fetch("https://api.prospectapis.com/v1/email/verify", {
  method: "POST",
  headers: { Authorization: `Bearer ${process.env.PROSPECTAPIS_KEY}`, "Content-Type": "application/json" },
  body: JSON.stringify({
    "emails": [
      "jane@acme.com",
      "sales@example.com"
    ]
  }),
});
if (!res.ok) throw new Error(`${res.status}: ${(await res.json().catch(() => ({}))).error ?? res.statusText}`);
const data = await res.json();
console.log(data);

import os, requests

res = requests.post(
    "https://api.prospectapis.com/v1/email/verify",
    headers={"Authorization": f"Bearer {os.environ['PROSPECTAPIS_KEY']}"},
    json={
        "emails": ["jane@acme.com", "sales@example.com"],
    },
    timeout=30,
)
res.raise_for_status()
data = res.json()
print(data)

Billing

Billing reserves before it serves: the call holds what it may cost, serves at most what that hold covers, and refunds the rest when the response closes. Any non-2xx answer refunds the whole hold, so a failed call costs nothing. The response reports your balance in X-Credits-Remaining.

Related

The email verification guide covers this area end to end. Previous operation: Poll a research brief. Next operation: Your email verification stats. Every operation, grouped by area, is on the API reference index.

Create a free account to get a key, then run the samples above with your own values (this call acts for real, so use real inputs).