PHP和PHPMAILER：如何在网站中实现邮件发送日志功能？

require 'path/to/PHPMailer/src/PHPMailer.php';
require 'path/to/PHPMailer/src/SMTP.php';
require 'path/to/PHPMailer/src/Exception.php';

CREATE TABLE `email_logs` (
  `id` int(11) NOT NULL AUTO_INCREMENT,
  `to_email` varchar(255) NOT NULL,
  `subject` varchar(255) NOT NULL,
  `message` text NOT NULL,
  `sent` tinyint(1) NOT NULL DEFAULT '0',
  `sent_date` datetime DEFAULT NULL,
  PRIMARY KEY (`id`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8;

function sendEmail($to, $subject, $message) {
    // 实例化PHPMailer对象
    $mail = new PHPMailerPHPMailerPHPMailer();

    // 配置SMTP服务器
    $mail->isSMTP();
    $mail->Host = 'smtp.example.com';
    $mail->SMTPAuth = true;
    $mail->Username = 'your_email@example.com';
    $mail->Password = 'your_password';
    $mail->SMTPSecure = 'ssl';
    $mail->Port = 465;

    // 设置邮件内容和收件人
    $mail->CharSet = 'UTF-8';
    $mail->setFrom('your_email@example.com', 'Your Name');
    $mail->addAddress($to);
    $mail->Subject = $subject;
    $mail->Body = $message;

    // 发送邮件
    if ($mail->send()) {
        // 邮件发送成功，将发送日志保存到数据库中
        $sent_date = date('Y-m-d H:i:s');
        $insert_query = "INSERT INTO email_logs (to_email, subject, message, sent, sent_date) VALUES ('$to', '$subject', '$message', 1, '$sent_date')";
        // 执行插入操作并检查是否成功
        if ($conn->query($insert_query) === TRUE) {
            echo "邮件发送成功！";
        } else {
            echo "邮件发送成功，但保存发送日志失败：" . $conn->error;
        }
    } else {
        echo "邮件发送失败：" . $mail->ErrorInfo;
    }
}

$to = 'recipient@example.com';
$subject = '邮件主题';
$message = '邮件正文';

sendEmail($to, $subject, $message);

$select_query = "SELECT * FROM email_logs";

$result = $conn->query($select_query);
if ($result->num_rows > 0) {
    while ($row = $result->fetch_assoc()) {
        echo "收件人：" . $row['to_email'] . "<br>";
        echo "主题：" . $row['subject'] . "<br>";
        echo "内容：" . $row['message'] . "<br>";
        echo "发送时间：" . $row['sent_date'] . "<br>";
        echo "<br>";
    }
} else {
    echo "没有邮件发送日志。";
}

$conn->close();