我的邮件总是会进入垃圾邮件文件夹，即使在代码点火器 php 中传递得很晚

我正在尝试在codeigniter帧中使用SMTP协议从我的Web服务器发送邮件 work.my 邮件总是延迟发送并发送垃圾邮件。我遵循了许多过去的保护措施，但我仍然没有解决这个问题。帮我解决这个问题。这是我的代码：

$config = Array('protocol' => 'smtp',
                       'smtp_host' => 'http://smtp.tfas.net/',
                       'smtp_port' => 465,
                       'smtp_user' => 'info@tfas.net',
                       'smtp_pass' => 'xxxxxxx',
                       'mailtype'  => 'html', 
                       'mailpath' => '/usr/sbin/sendmail',
                       'charset'   => 'utf-8'
                        );
      $this->load->library('email', $config);
      $this->email->set_newline("'r'n");
      if (file_exists($attachment_path)) 
      {
        $this->email->attach("$attachment_path");
        $this->email->from('info@tfas.net','TFAS MEMBER PORTAL');
        $this->email->reply_to('info@tfas.net','Help Center');
        $this->email->message($message);
        $this->email->to($to);
        $this->email->subject('Greetings From TFAS Member Portal');
      }
      else
      {
        $this->email->from('info@tfas.net','TFAS MEMBER PORTAL');
        $this->email->reply_to('info@tfas.net','Help Center');
        $this->email->message($message);
        $this->email->to($to);
        $this->email->subject('Greetings From TFAS Member Portal');
      }
        if($this->email->send())
        {
        return true;
        }
        else
        {
        return false;
        }

即使我已经浏览了这个链接https://github.com/ivantcholakov/codeigniter-phpmailer这是一个在codeigniter中使用phpmailer库发送邮件的教程，但同样的问题。