如何使用php codeigniter发送电子邮件？

$config['protocol'] = 'smtp';  // 选择邮件传输协议，一般为SMTP
$config['smtp_host'] = 'your_smtp_host';  // 邮件服务器主机名
$config['smtp_user'] = 'your_smtp_username';  // 邮件服务器用户名
$config['smtp_pass'] = 'your_smtp_password';  // 邮件服务器密码
$config['smtp_port'] = your_smtp_port;  // 邮件服务器端口号
$config['smtp_crypto'] = 'ssl';  // 邮件服务器的SSL加密方式，如果使用SSL连接，配置为'ssl'
$config['mailtype'] = 'html';  // 邮件内容类型，一般为html

$config['protocol'] = 'smtp';
$config['smtp_host'] = 'smtp.exmail.qq.com';
$config['smtp_user'] = 'your_email@example.com';
$config['smtp_pass'] = 'your_email_password';
$config['smtp_port'] = 465;
$config['smtp_crypto'] = 'ssl';
$config['mailtype'] = 'html';

<?php
defined('BASEPATH') OR exit('No direct script access allowed');

class EmailController extends CI_Controller {
    
    public function __construct() {
        parent::__construct();
        $this->load->library('email');  // 加载email库
    }

    public function sendEmail() {
        $this->email->from('your_email@example.com', 'Your Name');  // 发件人邮箱及发件人名称
        $this->email->to('recipient@example.com');  // 收件人邮箱
        $this->email->subject('Email Subject');  // 邮件主题
        $this->email->message('Email Content');  // 邮件内容
        
        if ($this->email->send()) {
            echo 'Email sent successfully.';
        } else {
            echo 'Email could not be sent.';
        }
    }
}

$this->load->controller('EmailController');
$this->EmailController->sendEmail();