如何在ng-click中自动发送邮件？

<button ng-click="sendEmail()">发送邮件</button>

app.controller('EmailController', function($scope, $http) {
  $scope.sendEmail = function() {
    $http.post('/send-email', { recipient: 'example@example.com', subject: '邮件主题', body: '邮件内容' })
      .then(function(response) {
        console.log('邮件发送成功');
      })
      .catch(function(error) {
        console.error('邮件发送失败', error);
      });
  };
});

app.post('/send-email', function(req, res) {
  const recipient = req.body.recipient;
  const subject = req.body.subject;
  const body = req.body.body;

  // 使用邮件发送库或API发送邮件
  // ...

  res.sendStatus(200);
});