BillionVerify + SendGrid 통합 - 전송 전 이메일 검증

사용자 가입 양식
      ↓
BillionVerify API (이메일 검증)
      ↓
유효? → SendGrid API (연락처 추가 + 전송)
유효하지 않음? → 거부 또는 로그

// Example: Verify email before sending welcome message via SendGrid

const axios = require('axios');
const sgMail = require('@sendgrid/mail');

sgMail.setApiKey(process.env.SENDGRID_API_KEY);

async function sendWelcomeEmail(email, name) {
  try {
    // Step 1: Verify email with BillionVerify
    const verificationResult = await axios.post(
      'https://api.billionverify.com/v1/verify',
      { email },
      {
        headers: {
          'Authorization': `Bearer ${process.env.BILLIONVERIFY_API_KEY}`,
          'Content-Type': 'application/json'
        }
      }
    );

    const { status, risk_level, is_disposable, is_catch_all, is_role } = verificationResult.data;

    // Step 2: Only send if email is valid and low-risk
    if (status === 'valid' && risk_level === 'low' && !is_disposable) {
      // Email is safe to send
      const msg = {
        to: email,
        from: 'welcome@yourdomain.com',
        subject: 'Welcome to Our Service!',
        text: `Hello ${name}, welcome to our platform!`,
        html: `<h1>Hello ${name}</h1><p>Welcome to our platform!</p>`,
      };

      await sgMail.send(msg);
      console.log(`✅ Welcome email sent to ${email}`);

      // Optional: Add to SendGrid marketing contacts
      await addToSendGridContacts(email, name, {
        email_verified: true,
        risk_level: 'low'
      });

      return { success: true, sent: true };
    } else if (status === 'invalid') {
      // Email is invalid - do not send
      console.log(`❌ Email ${email} is invalid. Not sending.`);
      return { success: false, reason: 'invalid_email' };
    } else if (is_disposable) {
      // Disposable email - block or flag
      console.log(`⚠️ Email ${email} is disposable. Flagging.`);
      return { success: false, reason: 'disposable_email' };
    } else {
      // Risky email - flag for review
      console.log(`⚠️ Email ${email} is risky (${risk_level}). Manual review needed.`);
      return { success: false, reason: 'risky_email', risk_level };
    }
  } catch (error) {
    console.error('Verification or sending error:', error);
    return { success: false, reason: 'api_error' };
  }
}

async function addToSendGridContacts(email, name, customFields) {
  const data = {
    contacts: [
      {
        email: email,
        first_name: name.split(' ')[0],
        last_name: name.split(' ')[1] || '',
        custom_fields: customFields
      }
    ]
  };

  await axios.put(
    'https://api.sendgrid.com/v3/marketing/contacts',
    data,
    {
      headers: {
        'Authorization': `Bearer ${process.env.SENDGRID_API_KEY}`,
        'Content-Type': 'application/json'
      }
    }
  );
}

// Usage example
app.post('/api/signup', async (req, res) => {
  const { email, name } = req.body;

  const result = await sendWelcomeEmail(email, name);

  if (result.success) {
    res.json({ message: 'Account created and welcome email sent!' });
  } else {
    res.status(400).json({
      error: 'Invalid email address',
      reason: result.reason
    });
  }
});

import requests
from sendgrid import SendGridAPIClient
from sendgrid.helpers.mail import Mail

BILLIONVERIFY_API_KEY = 'your_billionverify_api_key'
SENDGRID_API_KEY = 'your_sendgrid_api_key'

def send_welcome_email(email, name):
    # Step 1: Verify email with BillionVerify
    verification_response = requests.post(
        'https://api.billionverify.com/v1/verify',
        json={'email': email},
        headers={
            'Authorization': f'Bearer {BILLIONVERIFY_API_KEY}',
            'Content-Type': 'application/json'
        }
    )
    result = verification_response.json()

    # Step 2: Only send if valid and low-risk
    if result['status'] == 'valid' and result['risk_level'] == 'low' and not result.get('is_disposable'):
        # Safe to send
        message = Mail(
            from_email='welcome@yourdomain.com',
            to_emails=email,
            subject=f'Welcome {name}!',
            html_content=f'<h1>Hello {name}</h1><p>Welcome to our platform!</p>'
        )

        try:
            sg = SendGridAPIClient(SENDGRID_API_KEY)
            response = sg.send(message)
            print(f"✅ Email sent to {email}, status code: {response.status_code}")

            # Optional: Add to marketing contacts
            add_to_sendgrid_contacts(email, name, {
                'email_verified': True,
                'risk_level': 'low'
            })

            return {'success': True, 'sent': True}
        except Exception as e:
            print(f"Error sending email: {e}")
            return {'success': False, 'reason': 'sendgrid_error'}
    elif result['status'] == 'invalid':
        print(f"❌ Email {email} is invalid. Not sending.")
        return {'success': False, 'reason': 'invalid_email'}
    elif result.get('is_disposable'):
        print(f"⚠️ Email {email} is disposable. Blocking.")
        return {'success': False, 'reason': 'disposable_email'}
    else:
        print(f"⚠️ Email {email} is risky. Manual review needed.")
        return {'success': False, 'reason': 'risky_email'}

def add_to_sendgrid_contacts(email, name, custom_fields):
    data = {
        'contacts': [
            {
                'email': email,
                'first_name': name.split(' ')[0],
                'last_name': ' '.join(name.split(' ')[1:]) if len(name.split(' ')) > 1 else '',
                'custom_fields': custom_fields
            }
        ]
    }

    requests.put(
        'https://api.sendgrid.com/v3/marketing/contacts',
        json=data,
        headers={
            'Authorization': f'Bearer {SENDGRID_API_KEY}',
            'Content-Type': 'application/json'
        }
    )

const express = require('express');
const axios = require('axios');

const app = express();
app.use(express.json());

app.post('/webhook/sendgrid', async (req, res) => {
  const events = req.body;

  for (const event of events) {
    const { event: eventType, email } = event;

    // Handle bounces and blocks
    if (['bounce', 'dropped', 'blocked'].includes(eventType)) {
      console.log(`⚠️ SendGrid event: ${eventType} for ${email}`);

      // Verify email to check if it's permanently invalid
      const verificationResult = await axios.post(
        'https://api.billionverify.com/v1/verify',
        { email },
        {
          headers: {
            'Authorization': `Bearer ${process.env.BILLIONVERIFY_API_KEY}`,
            'Content-Type': 'application/json'
          }
        }
      );

      const { status } = verificationResult.data;

      if (status === 'invalid') {
        // Add to permanent suppression list
        await addToSuppressionList(email, 'invalid_email');
        console.log(`❌ Email ${email} added to suppression list`);
      }
    }
  }

  res.status(200).send('OK');
});

async function addToSuppressionList(email, reason) {
  // Add to SendGrid suppression list
  await axios.post(
    'https://api.sendgrid.com/v3/suppression/bounces',
    {
      emails: [
        {
          email: email,
          reason: reason
        }
      ]
    },
    {
      headers: {
        'Authorization': `Bearer ${process.env.SENDGRID_API_KEY}`,
        'Content-Type': 'application/json'
      }
    }
  );

  // Also log to your database for analytics
  // await logInvalidEmail(email, reason);
}

app.listen(3000, () => console.log('Webhook server running on port 3000'));