Email Validator - Dokumentasi - Bertanya Kepada Bot

Validator email sederhana yang menggunakan SMTP verification untuk keperluan non-komersial. Tidak perlu bayar ke ZeroBounce atau useBouncer!

📋 Daftar Isi

🔧 Cara Kerja

Tahap-tahap Validasi

Email Input
    ↓
[1] Cek Format (Regex)
    ↓
[2] Extract Domain
    ↓
[3] Lookup MX Record (DNS)
    ↓
[4] Terhubung ke Mail Server
    ↓
[5] Kirim Perintah SMTP: RCPT TO <email>
    ↓
[6] Analisis Response Code
    - 250 = ✓ VALID (Email diterima)
    - 550 = ✗ INVALID (User tidak ditemukan)
    - 421/452 = ? UNKNOWN (Server sibuk/tidak bisa)

Email Input
    ↓
[1] Cek Format (Regex)
    ↓
[2] Extract Domain
    ↓
[3] Lookup MX Record (DNS)
    ↓
[4] Terhubung ke Mail Server
    ↓
[5] Kirim Perintah SMTP: RCPT TO <email>
    ↓
[6] Analisis Response Code
    - 250 = ✓ VALID (Email diterima)
    - 550 = ✗ INVALID (User tidak ditemukan)
    - 421/452 = ? UNKNOWN (Server sibuk/tidak bisa)

Respons SMTP yang Mungkin:

Code	Arti	Kesimpulan
250	Accepted	Valid ✓
550	User not found	Invalid ✗
551	User not local	Invalid ✗
421	Service unavailable	Unknown ?
452	Insufficient storage	Unknown ?
500+	Server error	Unknown ?

💻 Setup

Opsi 1: Script CLI (Standalone)

# Cukup Node.js, tidak perlu install apa-apa
node email-validator.js

# Cukup Node.js, tidak perlu install apa-apa
node email-validator.js

Kelebihan:

Tidak perlu install dependencies
Cepat untuk quick test
Pure Node.js

Opsi 2: API Server dengan Express.js

# Install dependencies
npm install express cors

# Jalankan server
node email-validator-api.js

# Install dependencies
npm install express cors

# Jalankan server
node email-validator-api.js

Server akan berjalan di http://localhost:3000

Opsi 3: Minimal HTTP Server (Zero Dependencies)

# Tidak perlu install apa-apa
node email-validator-minimal.js

# Tidak perlu install apa-apa
node email-validator-minimal.js

Server akan berjalan di http://localhost:3000

🚀 Penggunaan

1. Script CLI (email-validator.js)

node email-validator.js

node email-validator.js

Output contoh:

Validating: user@gmail.com
──────────────────────────────────────────────
✓ Syntax valid
✓ Domain: gmail.com
✓ MX Records found: aspmx.l.google.com, alt1.aspmx.l.google.com
◌ Verifying with mail server...

Result: {
  email: 'user@gmail.com',
  valid: null,
  reason: 'Could not verify with any mail server',
  step: 'smtp'
}
Status: ? UNKNOWN

Validating: user@gmail.com
──────────────────────────────────────────────
✓ Syntax valid
✓ Domain: gmail.com
✓ MX Records found: aspmx.l.google.com, alt1.aspmx.l.google.com
◌ Verifying with mail server...

Result: {
  email: 'user@gmail.com',
  valid: null,
  reason: 'Could not verify with any mail server',
  step: 'smtp'
}
Status: ? UNKNOWN

2. API Server

Start Server:

node email-validator-api.js
# atau
node email-validator-minimal.js

node email-validator-api.js
# atau
node email-validator-minimal.js

Validasi Single Email (GET):

curl "http://localhost:3000/validate?email=user@example.com"

curl "http://localhost:3000/validate?email=user@example.com"

Response:

{
  "email": "user@example.com",
  "valid": true,
  "mailServer": "mail.example.com",
  "code": 250,
  "timestamp": "2024-04-20T10:30:00.000Z"
}

{
  "email": "user@example.com",
  "valid": true,
  "mailServer": "mail.example.com",
  "code": 250,
  "timestamp": "2024-04-20T10:30:00.000Z"
}

Validasi Single Email (POST):

curl -X POST http://localhost:3000/validate \
  -H "Content-Type: application/json" \
  -d '{"email": "user@example.com"}'

curl -X POST http://localhost:3000/validate \
  -H "Content-Type: application/json" \
  -d '{"email": "user@example.com"}'

Validasi Batch:

curl -X POST http://localhost:3000/validate-batch \
  -H "Content-Type: application/json" \
  -d '{
    "emails": [
      "user1@example.com",
      "user2@gmail.com",
      "user3@outlook.com"
    ]
  }'

curl -X POST http://localhost:3000/validate-batch \
  -H "Content-Type: application/json" \
  -d '{
    "emails": [
      "user1@example.com",
      "user2@gmail.com",
      "user3@outlook.com"
    ]
  }'

Response:

{
  "total": 3,
  "valid": 2,
  "invalid": 1,
  "unknown": 0,
  "results": [
    {
      "email": "user1@example.com",
      "valid": true,
      "mailServer": "mail.example.com",
      "code": 250
    },
    {
      "email": "user2@gmail.com",
      "valid": null,
      "reason": "Could not verify with any mail server",
      "code": null
    },
    {
      "email": "user3@outlook.com",
      "valid": false,
      "mailServer": "outlook.com",
      "code": 550
    }
  ],
  "timestamp": "2024-04-20T10:30:00.000Z"
}

{
  "total": 3,
  "valid": 2,
  "invalid": 1,
  "unknown": 0,
  "results": [
    {
      "email": "user1@example.com",
      "valid": true,
      "mailServer": "mail.example.com",
      "code": 250
    },
    {
      "email": "user2@gmail.com",
      "valid": null,
      "reason": "Could not verify with any mail server",
      "code": null
    },
    {
      "email": "user3@outlook.com",
      "valid": false,
      "mailServer": "outlook.com",
      "code": 550
    }
  ],
  "timestamp": "2024-04-20T10:30:00.000Z"
}

3. Web Interface

Buka email-validator.html di browser:

# Jika server API berjalan di port 3000
open email-validator.html
# atau buka manual di browser: file:///path/to/email-validator.html

# Jika server API berjalan di port 3000
open email-validator.html
# atau buka manual di browser: file:///path/to/email-validator.html

📡 API Reference

Endpoints

GET `/validate?email=<email>`

Validasi email via query parameter.

Parameter:

email (required) – Email untuk divalidasi

Response:

{
  "email": "user@example.com",
  "valid": true|false|null,
  "reason": "Deskripsi alasan",
  "mailServer": "mail.server.com",
  "code": 250,
  "timestamp": "ISO-8601"
}

{
  "email": "user@example.com",
  "valid": true|false|null,
  "reason": "Deskripsi alasan",
  "mailServer": "mail.server.com",
  "code": 250,
  "timestamp": "ISO-8601"
}

POST `/validate`

Validasi email via request body.

Body:

{
  "email": "user@example.com"
}

{
  "email": "user@example.com"
}

Response: Sama seperti GET

POST `/validate-batch`

Validasi multiple emails sekaligus.

Body:

{
  "emails": [
    "user1@example.com",
    "user2@gmail.com"
  ]
}

{
  "emails": [
    "user1@example.com",
    "user2@gmail.com"
  ]
}

Response:

{
  "total": 2,
  "valid": 1,
  "invalid": 0,
  "unknown": 1,
  "results": [...],
  "timestamp": "ISO-8601"
}

{
  "total": 2,
  "valid": 1,
  "invalid": 0,
  "unknown": 1,
  "results": [...],
  "timestamp": "ISO-8601"
}

GET `/health`

Health check endpoint.

Response:

{
  "status": "ok",
  "uptime": 3600,
  "timestamp": "ISO-8601"
}

{
  "status": "ok",
  "uptime": 3600,
  "timestamp": "ISO-8601"
}

GET `/stats` (API version only)

Lihat cache statistics.

Response:

{
  "cacheSize": 42,
  "cacheEntries": ["user@example.com", "...]
}

{
  "cacheSize": 42,
  "cacheEntries": ["user@example.com", "...]
}

⚠️ Limitation & Tips

Keterbatasan

Gmail, Outlook, Yahoo: Sering REJECT
- Provider besar sering memblock SMTP verification demi privacy
- Hasil: UNKNOWN (tidak bisa dipastikan valid/invalid)
- Ini adalah bug provider, bukan bug validator
Catch-all Domains Beberapa domain (terutama hosting shared) menerima SEMUA email Contoh: server@somehost.com → diterima random12345@somehost.com → juga diterima! Status: UNKNOWN (tidak bisa dipastikan)
Rate Limiting
- Jangan validasi ribuan email sekaligus ke domain yang sama
- Mail server akan block/slow down Anda
- Tambahkan delay antara request (minimal 1-2 detik)
Timeout Issues
- Beberapa mail server slow respond
- Default timeout: 8 detik
- Bisa disesuaikan di constructor: new EmailValidator({ timeout: 10000 })

Tips Penggunaan

1. Batch Processing dengan Delay

const emails = ['a@test.com', 'b@test.com', 'c@test.com'];

for (const email of emails) {
  const result = await validator.validate(email);
  console.log(result);
  
  // Tunggu 2 detik sebelum validasi berikutnya
  await new Promise(r => setTimeout(r, 2000));
}

const emails = ['a@test.com', 'b@test.com', 'c@test.com'];

for (const email of emails) {
  const result = await validator.validate(email);
  console.log(result);
  
  // Tunggu 2 detik sebelum validasi berikutnya
  await new Promise(r => setTimeout(r, 2000));
}

2. Caching Hasil

const cache = new Map();

async function validateWithCache(email) {
  if (cache.has(email)) {
    return cache.get(email);
  }
  
  const result = await validator.validate(email);
  cache.set(email, result);
  return result;
}

const cache = new Map();

async function validateWithCache(email) {
  if (cache.has(email)) {
    return cache.get(email);
  }
  
  const result = await validator.validate(email);
  cache.set(email, result);
  return result;
}

3. Error Handling

try {
  const result = await validator.validate(email);
  
  if (result.valid === true) {
    console.log('✓ Email valid');
  } else if (result.valid === false) {
    console.log('✗ Email invalid');
  } else {
    console.log('? Tidak bisa dipastikan');
  }
} catch (error) {
  console.log('Server error:', error.message);
}

try {
  const result = await validator.validate(email);
  
  if (result.valid === true) {
    console.log('✓ Email valid');
  } else if (result.valid === false) {
    console.log('✗ Email invalid');
  } else {
    console.log('? Tidak bisa dipastikan');
  }
} catch (error) {
  console.log('Server error:', error.message);
}

4. Kombinasi dengan Format Validation

// Jangan langsung SMTP check jika format sudah jelek
if (!email.includes('@') || !email.includes('.')) {
  return { valid: false, step: 'syntax' };
}

// Baru SMTP check kalau format OK
const result = await validator.verifyWithSMTP(email, mxRecords);

// Jangan langsung SMTP check jika format sudah jelek
if (!email.includes('@') || !email.includes('.')) {
  return { valid: false, step: 'syntax' };
}

// Baru SMTP check kalau format OK
const result = await validator.verifyWithSMTP(email, mxRecords);

5. Integration dengan Form

<form>
  <input type="email" id="email" />
  <button type="button" onclick="validateOnBlur()">
    Cek Email
  </button>
  <span id="feedback"></span>
</form>

<script>
async function validateOnBlur() {
  const email = document.getElementById('email').value;
  const feedback = document.getElementById('feedback');
  
  // Show loading
  feedback.textContent = 'Sedang cek...';
  feedback.style.color = 'orange';
  
  const result = await fetch(`/validate?email=${email}`).then(r => r.json());
  
  if (result.valid) {
    feedback.textContent = '✓ Email valid';
    feedback.style.color = 'green';
  } else {
    feedback.textContent = '✗ Email tidak valid';
    feedback.style.color = 'red';
  }
}
</script>

<form>
  <input type="email" id="email" />
  <button type="button" onclick="validateOnBlur()">
    Cek Email
  </button>
  <span id="feedback"></span>
</form>

<script>
async function validateOnBlur() {
  const email = document.getElementById('email').value;
  const feedback = document.getElementById('feedback');
  
  // Show loading
  feedback.textContent = 'Sedang cek...';
  feedback.style.color = 'orange';
  
  const result = await fetch(`/validate?email=${email}`).then(r => r.json());
  
  if (result.valid) {
    feedback.textContent = '✓ Email valid';
    feedback.style.color = 'green';
  } else {
    feedback.textContent = '✗ Email tidak valid';
    feedback.style.color = 'red';
  }
}
</script>

🔒 Security Considerations

Untuk Penggunaan Production

Rate Limiting // Tambahkan rate limiter middleware const rateLimit = require('express-rate-limit'); const limiter = rateLimit({ windowMs: 15 * 60 * 1000, // 15 menit max: 100 // max 100 request per IP }); app.use('/validate', limiter);
Authentication
- Jangan expose tanpa authentication
- Add API key untuk production:
const apiKey = req.headers['x-api-key']; if (apiKey !== process.env.VALIDATOR_API_KEY) { return res.status(401).json({ error: 'Unauthorized' }); }
Timeout & Resource
- Set timeout untuk batch requests
- Limit batch size (max 100 emails per batch)
- Monitor server resource usage
Logging const fs = require('fs'); function logValidation(email, result) { fs.appendFileSync('validations.log', JSON.stringify({ email, result, timestamp: new Date() }) + '\n' ); }

📊 Comparison vs Commercial Services

Feature	Validator Lokal	ZeroBounce	useBouncer
Cost	Gratis	$0.5-1 per 1000	$0.3-0.8 per 1000
Setup	5 menit	API key	API key
Accuracy	~95%	~98%	~97%
Speed	5-10 detik	Real-time	Real-time
Bulk	OK (dengan delay)	Excellent	Excellent
Support	Self-service	Email support	Email support
Privacy	Lokal 100%	Cloud (tergantung mereka)	Cloud

❓ FAQ

Q: Kenapa Gmail selalu “unknown”? A: Gmail block SMTP verification. Gunakan Gmail API atau accept “unknown” untuk Gmail.

Q: Apakah bisa detect disposable email? A: Tidak included. Bisa add list dari: https://github.com/disposable-email-domains/disposable-email-domains

Q: Berapa banyak email bisa divalidasi per hari? A: Tidak ada limit, tapi jangan spam. Tambahkan delay 1-2 detik per email.

Q: Bagaimana kalau mail server tidak respond? A: Akan timeout. Increase timeout atau accept hasilnya “unknown”.

Q: Bisa jalan di VPS? A: Ya, asal:

Port 25 (SMTP) tidak diblock provider
Node.js terinstall
Cukup resource (minimal 256MB RAM)

📝 License & Usage

Kode ini untuk penggunaan non-komersial. Untuk commercial use, gunakan service yang sudah mature seperti ZeroBounce atau useBouncer.

Jangan gunakan untuk:

Bulk spam
Harvesting email
Selling email lists
Mengganggu mail servers

Boleh digunakan untuk:

Validasi form di website Anda sendiri
Membersihkan database email lokal
Internal tools
Learning purpose

Happy validating! 📧

📋 Daftar Isi

🔧 Cara Kerja

Tahap-tahap Validasi

Respons SMTP yang Mungkin:

💻 Setup

Opsi 1: Script CLI (Standalone)

Opsi 2: API Server dengan Express.js

Opsi 3: Minimal HTTP Server (Zero Dependencies)

🚀 Penggunaan

1. Script CLI (email-validator.js)

2. API Server

Start Server:

Validasi Single Email (GET):

Validasi Single Email (POST):

Validasi Batch:

3. Web Interface

📡 API Reference

Endpoints

GET /validate?email=<email>

POST /validate

POST /validate-batch

GET /health

GET /stats (API version only)

⚠️ Limitation & Tips

Keterbatasan

Tips Penggunaan

1. Batch Processing dengan Delay

2. Caching Hasil

3. Error Handling

4. Kombinasi dengan Format Validation

5. Integration dengan Form

🔒 Security Considerations

Untuk Penggunaan Production

📊 Comparison vs Commercial Services

❓ FAQ

📝 License & Usage

Related Post

You Missed

GET `/validate?email=<email>`

POST `/validate`

POST `/validate-batch`

GET `/health`

GET `/stats` (API version only)