How to implement binding mailbox in phpmailer

<?php
return array (
 &#39;email_host&#39; => &#39;smtp.aliyun.com&#39;,
 &#39;email_port&#39; => &#39;25&#39;,
 &#39;email_username&#39; => &#39;diandodo@aliyun.com&#39;,
 &#39;email_password&#39; => &#39;xxxxxx&#39;,
 &#39;email_from&#39; => &#39;diandodo@aliyun.com&#39;,
 &#39;email_fromname&#39; => &#39;点多多&#39;,
 &#39;email_subject&#39; => &#39;助店宝商户激活邮箱&#39;,
 &#39;email_body&#39; => "尊敬的用户{$username}您好:
    您的激活码为<font color=&#39;red&#39;>{$code}</font>,请将激活码输入进行验证! 激活码有效期为6分钟^_^",
);

// 发送邮件
private function _sendEmail($email,$code,$username = '') {
    import('@.ORG.phpmailer');
    $mail = new PHPMailer(); //建立邮件发送类,类名不一定与引入的文件名相同
    $mail->CharSet = "UTF-8";
    $mail->IsSMTP(); // 使用SMTP方式发送
    $mail->Host = C('email_host'); // 您的企业邮局域名
    $mail->SMTPAuth = true; // 启用SMTP验证功能
    $mail->Username = C('email_username'); // 邮局用户名(请填写完整的email地址)
    $mail->Password = C('email_password'); // 邮局密码
    $mail->Port=C('email_port');
    $mail->From = C('email_from'); //邮件发送者email地址
    $mail->FromName = C('email_fromname');
    $mail->AddAddress("$email", "$username");
    $mail->IsHTML(true); // set email format to HTML //是否使用HTML格式
    $mail->Subject = C('email_subject'); //邮件标题
    $email_body = "尊敬的用户<strong>{$username}</strong>您好:
    您的激活码为<font color=&#39;red&#39;>{$code}</font>,请将激活码输入进行验证! 激活码有效期为6分钟^_^";
    $mail->Body = $email_body; //邮件内容，上面设置HTML，则可以是HTML
    if(!$mail->Send())
    {
      return array(&#39;status&#39;=>2,&#39;info&#39;=>$mail->ErrorInfo);
    } else {
      return array(&#39;status&#39;=>1,&#39;info&#39;=>&#39;发送成功&#39;);;
    }
}

// 发送邮箱激活码
public function sendActivationcode() {
    session($this->activationtime, null);
    $activationtime = session($this->activationtime);
    $email = $this->_post('email', 'trim');
    if (IS_AJAX && (!$activationtime || time() > $activationtime)) {
      $activationcode = rand(1000, 9999);
      $res = $this->_sendEmail($email,$activationcode,$this->user['username']);
      if($res['status'] == 1) {
        //设置发送限制时间
        session($this->activationtime, time() + 50);
        session($this->activationcode, array('code' => $activationcode, 'time' => time() + 600));
        $this->ajaxReturn(array('result' => true));
      } else {
        //发送失败写入日志文件
        $log = date('Y-m-d H:i:s') . " 发送失败:{$res['info']}" . PHP_EOL;
        file_put_contents(RUNTIME_PATH . 'Log/activationcode.log', $log, FILE_APPEND);
        $this->ajaxReturn(array('result' => false, 'error' => $res['info']));
      }
    } else {
      $this->ajaxReturn(array('result' => false, 'error' => '错误的请求'));
    }
}

// 绑定邮箱
public function bind_email() {
    if (IS_POST) {
      // 获取验证码
      $activationcode = $this->_post('activationcode','trim');
      $email = $this->_post('email','trim');
      $session_activationcode = session($this->activationcode);
      if (time() > $session_activationcode['time'] || $activationcode != $session_activationcode['code']) {
        $this->error('验证码有误');
      } else {
        M('User')->where(array('id'=>$this->user['id']))->save(array('email'=>$email));
        $this->success('绑定成功',U('Account/my'));
      }
    } else {
      $this->display();
    }
}