如何使用swiftmailer将失败的邮件记录到数据库中

CREATE TABLE failed_emails (
    id INT AUTO_INCREMENT PRIMARY KEY,
    recipient VARCHAR(255) NOT NULL,
    subject VARCHAR(255) NOT NULL,
    body TEXT NOT NULL,
    error_message TEXT,
    created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP
);

use Swift_Events_SendEvent;
use Swift_Events_SendListener;

// 自定义的失败邮件事件监听器
class FailedEmailListener implements Swift_Events_SendListener
{
    public function beforeSendPerformed(Swift_Events_SendEvent $event)
    {
        // 在邮件发送之前执行的操作
    }

    public function sendPerformed(Swift_Events_SendEvent $event)
    {
        // 在邮件发送之后执行的操作
        if (!$event->isSuccessful()) {
            // 邮件发送失败，将失败信息记录到数据库中
            $failedEmail = [
                'recipient' => $event->getMessage()->getTo(),
                'subject' => $event->getMessage()->getSubject(),
                'body' => $event->getMessage()->getBody(),
                'error_message' => $event->getFailedRecipients(),
            ];
            // 将$failedEmail保存到数据库表中
            // 例如使用PDO进行数据库操作
            $pdo = new PDO('mysql:host=localhost;dbname=mydatabase', 'username', 'password');
            $stmt = $pdo->prepare('INSERT INTO failed_emails (recipient, subject, body, error_message) VALUES (?, ?, ?, ?)');
            $stmt->execute([$failedEmail['recipient'], $failedEmail['subject'], $failedEmail['body'], $failedEmail['error_message']]);
        }
    }
}

// 创建SwiftMailer实例
$mailer = new Swift_Mailer($transport);

// 创建失败邮件事件监听器实例
$listener = new FailedEmailListener();

// 注册失败邮件事件监听器
$mailer->registerPlugin($listener);

// 创建邮件对象并设置相关属性
$message = new Swift_Message();
$message->setTo('recipient@example.com');
$message->setFrom('sender@example.com');
$message->setSubject('Hello');
$message->setBody('This is the email body.');

// 发送邮件
$result = $mailer->send($message);

if ($result) {
    echo '邮件发送成功';
} else {
    echo '邮件发送失败';
}