mailboxlayer

How to Use This API

1. Check Email Address

https://api.mailboxlayer.com/check?access_key=YOUR_KEY&email=test@example.com

Returns format_valid, mx_found, smtp_check, score (0-1), did_you_mean suggestions, and disposable/role account flags.

2. Validate with SMTP Check

https://api.mailboxlayer.com/check?access_key=YOUR_KEY&email=john@gmail.com&smtp=1

Enable SMTP verification (connection to mail server) for deeper validation. May take 3-10 seconds.

3. JavaScript — Signup Email Validator

async function validateEmail(email, apiKey) {
  const resp = await fetch(
    `https://api.mailboxlayer.com/check` +
    `?access_key=${apiKey}&email=${encodeURIComponent(email)}&smtp=1`
  );
  const data = await resp.json();
  
  return {
    valid: data.format_valid && data.mx_found,
    score: data.score,
    suggestion: data.did_you_mean || null,
    isDisposable: data.disposable,
    isRoleAccount: data.role,
    reason: !data.format_valid ? 'Invalid format' :
            !data.mx_found ? 'No mail server' :
            data.disposable ? 'Disposable email' : 'Valid'
  };
}

async function onSignup(email) {
  const result = await validateEmail(email, 'YOUR_API_KEY');
  if (!result.valid) {
    alert(`Invalid email: ${result.reason}`);
    if (result.suggestion) {
      alert(`Did you mean: ${result.suggestion}?`);
    }
    return false;
  }
  return true;
}

onSignup('user@gmial.com').then(console.log);

4. Python — Email List Cleaner

import requests

def check_email(email, api_key):
    resp = requests.get(
        'https://api.mailboxlayer.com/check',
        params={'access_key': api_key, 'email': email, 'smtp': 0}
    )
    return resp.json()

def clean_email_list(emails, api_key):
    valid = []
    invalid = []
    for email in emails:
        result = check_email(email, api_key)
        if result.get('format_valid') and result.get('mx_found'):
            valid.append(email)
        else:
            invalid.append(email)
    
    print(f"Valid: {len(valid)}, Invalid: {len(invalid)}")
    if invalid:
        print("Invalid emails:")
        for e in invalid[:5]:
            print(f"  {e}")

clean_email_list(['user@gmail.com', 'fake@nonexistent-domain-abc123.com'], 'YOUR_KEY')