Email Open and Click Tracking for Campaigns

Email Open and Click Tracking Setup

Open tracking works via pixel—transparent 1×1 px image embedded in email. Click tracking uses redirect links. Most ESPs do this automatically, but sometimes custom implementation stores data in your own database.

Pixel Tracking (Opens)

// GET /api/email/track/open/:token
app.get('/api/email/track/open/:token', async (req, res) => {
  const { token } = req.params;

  // Don't await—don't block response
  trackEmailOpen(token, {
    ip: req.ip,
    userAgent: req.get('User-Agent') ?? '',
    timestamp: new Date(),
  }).catch(console.error);

  // Return 1x1 transparent GIF
  const pixel = Buffer.from(
    'R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7',
    'base64'
  );

  res.writeHead(200, {
    'Content-Type': 'image/gif',
    'Content-Length': pixel.length,
    'Cache-Control': 'no-store, no-cache, must-revalidate',
  });
  res.end(pixel);
});

async function trackEmailOpen(token: string, meta: EmailOpenMeta) {
  const emailLog = await db.emailLogs.findByTrackingToken(token);
  if (!emailLog) return;

  await db.emailOpens.create({
    email_log_id: emailLog.id,
    ip: meta.ip,
    user_agent: meta.userAgent,
    opened_at: meta.timestamp,
  });
}

Click Tracking (Redirects)

// GET /api/email/track/click/:token?url=...
app.get('/api/email/track/click/:token', async (req, res) => {
  const { token } = req.query.url;
  const targetUrl = req.query.url;

  trackEmailClick(token, {
    url: targetUrl,
    ip: req.ip,
    timestamp: new Date(),
  }).catch(console.error);

  res.redirect(targetUrl);
});

Email Template Integration

<!-- In your email template -->
<img src="https://your-app.com/api/email/track/open/{{trackingToken}}"
     alt="" width="1" height="1" style="display:none;"/>

<a href="https://your-app.com/api/email/track/click/{{trackingToken}}?url={{urlencoded(cta_url)}}">
  {{cta_text}}
</a>

Timeline

Basic implementation—1–2 days. With dashboard and cohort analysis—3–5 days.