Very simple but fast (file based) mail queue

MailQueueService.class.php

<?php

class MailQueueService()
{
  public function getMailsFolder()
  {
    return '/tmp/mails/';
  }

  public function popSpooledMail()
  {
    foreach (new DirectoryIterator($this->getMailsFolder()) as $file_info) {
      if($file_info->isDot()) continue;
      if ($file_info->getExtension() == 'json')
      {
          $file_path = $file_info->getPathname();
          $content = @file_get_contents($file_path);

          if ($content)
          {
              if (@unlink($file_path))
              {
                  return json_decode($content, true);
              }
          }
      }
    }
    
    throw new \Exception('No mail in the queue!');
  }
  
  public function pushMail($values)
  {
    file_put_contents($this->generateUniqueFileNameForSpooledMail(), json_encode($values));
  }

  protected function generateUniqueFileNameForSpooledMail()
  {
    $uuid = substr(sha1(uniqid('', true) . microtime(true)), 0, 32);

    $file_name = $this->getMailsFolder() . $uuid . '.json';

    while (file_exists($file_name))
    {
        $uuid = substr(sha1(uniqid('', true) . microtime(true)), 0, 32);
        $file_name = $this->getMailsFolder() . $uuid . '.json';
    }

    return $file_name;
  }
}

usage.php

<?php

$queue = new \MailQueueService();
$queue->pushMail(array('subject' => 'hai', 'body' => 'hai body', 'email' => 'hans@example.org'));
$queue->pushMail(array('subject' => 'hai2', 'body' => 'hai body', 'email' => 'hans@example.org'));
$queue->pushMail(array('subject' => 'hai3', 'body' => 'hai body', 'email' => 'hans@example.org'));

$count = 5;

try
{
  while ($count > 0)
  {
    $mail_values = $queue->popSpooledMail();
    /* FIXME: code to send the mail values */
    $count--;
  }
} catch (\Exception $exception)
{
  /* done! */
}