PHP和swoole如何实现高并发的电子邮件发送和处理？

<?php

use SwooleCoroutineHTTPClient;

// 创建一个HTTP客户端
$client = new Client('smtp.example.com', 25, false);

// 连接到SMTP服务器
$client->connect();

// 发送邮件相关的命令
$client->send("EHLO client.example.com
");
$client->send("AUTH LOGIN
");
$client->send(base64_encode('example_username') . "
");
$client->send(base64_encode('example_password') . "
");
$client->send("MAIL FROM: <from@example.com>
");
$client->send("RCPT TO: <to@example.com>
");
$client->send("DATA
");
$client->send("Subject: Hello
");
$client->send("From: from@example.com
");
$client->send("To: to@example.com
");
$client->send("Content-Type: text/plain; charset=UTF-8
");
$client->send("
");
$client->send("This is the message body.
");
$client->send(".
");
$client->send("QUIT
");

// 接收并打印邮件发送的结果
while (true) {
    $response = $client->recv();
    if ($response === '') {
        break;
    }
    echo $response;
}

// 关闭连接
$client->close();

<?php

use SwooleCoroutineIMAP;

// 连接到IMAP服务器
$server = '{imap.example.com:993/ssl/novalidate-cert}';
$mailbox = new IMAP($server . 'INBOX', 'username', 'password');

// 打开邮箱
$mailbox->openMailbox();

// 获取邮件列表
$list = $mailbox->listMessages();

// 遍历邮件列表
foreach ($list as $uid) {
    // 获取邮件内容
    $message = $mailbox->getMessageByUID($uid);

    // 打印邮件内容
    var_dump($message);

    // 删除邮件
    $mailbox->deleteMessageByUID($uid);
}

// 关闭连接
$mailbox->closeMailbox();