Email verification API: syntax, MX and SMTP checks in one call

curl -X POST "https://api.searlo.tech/api/v1/email-verifier/verify" \
  -H "x-api-key: YOUR_API_KEY" \
  -H "content-type: application/json" \
  -d '{ "email": "[email protected]" }'

import time
import requests
from concurrent.futures import ThreadPoolExecutor

ENDPOINT = "https://api.searlo.tech/api/v1/email-verifier/verify"
HEADERS = {"x-api-key": "YOUR_API_KEY"}
PER_MINUTE = 80  # under the default limits of 100 a minute and 5,000 an hour


def verify(email):
    r = requests.post(ENDPOINT, headers=HEADERS, json={"email": email}, timeout=60)
    if r.status_code == 429 or r.status_code >= 500:
        return email, None                        # not charged: retry later
    if r.status_code == 400:                      # rejected before billing
        return email, {"status": "invalid", "reason": "rejected_format"}
    r.raise_for_status()
    return email, r.json()["data"]


raw = ["[email protected]", "[email protected] ", "[email protected]", "[email protected]"]
emails = sorted({e.strip().lower() for e in raw})  # a repeat check is billed again

results, retry_later = {}, []
with ThreadPoolExecutor(max_workers=4) as pool:
    futures = []
    for email in emails:
        futures.append(pool.submit(verify, email))
        time.sleep(60 / PER_MINUTE)               # pace requests under the limit
    for future in futures:
        email, data = future.result()
        if data is None or data.get("retryable"):
            retry_later.append(email)
        else:
            results[email] = data

for email, data in results.items():
    print(email, data["status"], data.get("reason"), data.get("didYouMean"))
print("retry later:", retry_later)

const ENDPOINT = "https://api.searlo.tech/api/v1/email-verifier/verify";
const PER_MINUTE = 80; // under the default limits of 100 a minute and 5,000 an hour
const sleep = (ms) => new Promise((resolve) => setTimeout(resolve, ms));

async function verify(email) {
  const res = await fetch(ENDPOINT, {
    method: "POST",
    headers: { "x-api-key": "YOUR_API_KEY", "content-type": "application/json" },
    body: JSON.stringify({ email }),
    signal: AbortSignal.timeout(60_000),
  });
  if (res.status === 429 || res.status >= 500) return { email, retryLater: true }; // not charged
  const body = await res.json();
  if (!res.ok) return { email, status: "invalid", reason: body.message }; // 400: not charged
  return body.data;
}

// De-duplicate first: a repeat check of the same address is billed again.
const emails = [...new Set(
  ["[email protected]", "[email protected]", "[email protected]"].map((e) => e.trim().toLowerCase()),
)];

const pending = [];
for (const email of emails) {
  pending.push(verify(email));      // start one check...
  await sleep(60_000 / PER_MINUTE); // ...then wait, so the rate stays under the limit
}

for (const r of await Promise.all(pending)) {
  if (r.retryLater || r.retryable) console.log(r.email, "retry later");
  else console.log(r.email, r.status, r.reason ?? "", r.didYouMean ?? "");
}

{
  "statusCode": 200,
  "data": {
    "email": "[email protected]",
    "status": "valid",
    "domain": "example.com",
    "message": "The mailbox exists and accepts mail.",
    "score": 97,
    "reason": "mailbox_exists",
    "retryable": false,
    "didYouMean": null,
    "details": {
      "format": "valid",
      "mailboxStatus": "valid",
      "mailboxType": "professional",
      "mailboxExchange": "mx.example.com",
      "domainStatus": "valid",
      "mailProvider": "self-hosted",
      "catchAll": false,
      "rcptUnreliable": false,
      "disposable": false,
      "roleAccount": false,
      "freeProvider": false,
      "smtpServer": true,
      "smtpCheck": true,
      "mxFound": true
    },
    "verifiedAt": "2026-09-29T10:15:04.000Z",
    "source": "searlo"
  },
  "message": "Email verified",
  "success": true
}

{
  "statusCode": 200,
  "data": {
    "email": "[email protected]",
    "status": "unknown",
    "domain": "slow-mail.example",
    "message": "The mail server asked us to try again later.",
    "score": 40,
    "reason": "greylisted",
    "retryable": true,
    "didYouMean": null,
    "details": {
      "format": "valid",
      "mailboxStatus": "unknown",
      "mailboxType": "role",
      "mailboxExchange": "mx1.slow-mail.example",
      "domainStatus": "valid",
      "mailProvider": null,
      "catchAll": null,
      "rcptUnreliable": null,
      "disposable": false,
      "roleAccount": true,
      "freeProvider": false,
      "smtpServer": true,
      "smtpCheck": null,
      "mxFound": true
    },
    "verifiedAt": "2026-09-29T10:15:09.000Z",
    "source": "searlo"
  },
  "message": "Email verified",
  "success": true
}