Real-Time Form Verification

// Verify on blur — check when user leaves the field
emailInput.addEventListener('blur', async () => {
  const email = emailInput.value;
  const res = await fetch(
    `/api/verify-email?email=${email}`  // Your backend proxy
  );
  const data = await res.json();

  if (data.disposable === 'true') {
    showError('Please use a permanent email address.');
  } else if (data.result === 'invalid') {
    showError('This email doesn\'t seem to exist. Check for typos?');
  } else if (data.did_you_mean) {
    showSuggestion(`Did you mean ${data.did_you_mean}?`);
  } else if (data.role === 'true') {
    showWarning('Looks like a shared inbox. Personal email?');
  }
});