PHP实现邮件数量控制的技巧

//连接SMTP服务器
$mail = new phpMailer(true);
$mail->SMTPDebug = 0;
$mail->iSSMTP();
$mail->Host = 'smtp.example.com';
$mail->SMTPAuth = true;
$mail->Username = 'username';
$mail->PassWord = 'password';
$mail->SMTPSecure = 'ssl';
$mail->Port = 465;

//添加收件人、主题、正文等信息

//发送邮件
if ($mail->send()) {
  echo '邮件发送成功';
} else {
  echo '邮件发送失败';
}

//获取SMTP服务器的发送限制
$limit = $mail->getSMTPInstance()->getSendLimit();
if ($limit) {
  echo 'SMTP服务器每小时最多可以发送'.$limit.'封邮件';
}

//将待发送的邮件添加到队列中
function addToQueue($to, $subject, $message) {
  $queueFile = 'mail_queue.txt';
  $data = serialize(array('to'=>$to, 'subject'=>$subject, 'message'=>$message));
  file_put_contents($queueFile, $data."
", FILE_APPEND | LOCK_EX);
}

//按照队列中的顺序发送邮件
function processQueue() {
  $queueFile = 'mail_queue.txt';
  if (!file_exists($queueFile) || !is_readable($queueFile)) {
    return false;
  }
  $f = fopen($queueFile, 'r');
  while ($data = fgets($f)) {
    $mail = unserialize(trim($data));
    $to = $mail['to'];
    $subject = $mail['subject'];
    $message = $mail['message'];
    //发送邮件
    //...
  }
  fclose($f);
  //清空队列
  file_put_contents($queueFile, '');
  return true;
}

//连接数据库
$conn = new Mysqli('localhost', 'username', 'password', 'database');
if ($conn->connect_error) {
  die('数据库连接失败：'.$conn->connect_error);
}

//查询发送数量
$count = $conn->query("SELECT COUNT(*) as total FROM emails WHERE sent_date >= DATE_SUB(NOW(), INTERVAL 1 HOUR)");
if (!$count) {
  die('查询失败：'.$conn->error);
}
$row = $count->fetch_assoc();
$total = $row['total'];

//判断发送限制
if ($total >= 100) {
  die('发送数量已达限制');
}

//插入邮件信息
$stmt = $conn->prepare("INSERT INTO emails (recipient, subject, content, sent_date) VALUES (?, ?, ?, NOW())");
$stmt->bind_param('sss', $to, $subject, $content);
if (!$stmt->execute()) {
  die('邮件发送失败：'.$conn->error);
} else {
  echo '邮件已添加到队列';
}
$stmt->close();
$conn->close();