【初心者向け】SendGridカテゴリー（category）設定で一斉送信メールを見える化｜GAS・APIで開封率を追跡！

const SENDGRID_API_KEY = 'YOUR_API_KEY';
const SENDGRID_ENDPOINT = 'https://api.sendgrid.com/v3/mail/send';

function sendMailWithCategory(to, subject, body, category) {
  const payload = {
    personalizations: [{
      to: [{ email: to }],
      subject: subject,
      categories: [category]
    }],
    from: { email: 'your_email@example.com' },
    content: [{ type: 'text/plain', value: body }]
  };

  const options = {
    method: 'post',
    contentType: 'application/json',
    headers: { Authorization: 'Bearer ' + SENDGRID_API_KEY },
    payload: JSON.stringify(payload)
  };

  UrlFetchApp.fetch(SENDGRID_ENDPOINT, options);
}

curl -X POST \
  https://api.sendgrid.com/v3/mail/send \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "personalizations": [{
      "to": [{"email": "test@example.com"}],
      "subject": "カテゴリー付きテスト",
      "categories": ["follow-up"]
    }],
    "from": {"email": "your_email@example.com"},
    "content": [{"type": "text/plain", "value": "本文です"}]
  }'

const sgMail = require('@sendgrid/mail');
sgMail.setApiKey(process.env.SENDGRID_API_KEY);

const msg = {
  to: 'test@example.com',
  from: 'your_email@example.com',
  subject: 'カテゴリー付きテスト',
  text: '本文です',
  categories: ['event-invite']
};

sgMail.send(msg);