PayPal IPN 未返回已验证

我正在尝试让 IPN 从PayPal工作，但它一直返回INVALID而不是VERIFIED，我看不到我做错了什么。

目前，我有 2 个 php 文件，使用 PayPal 开发人员站点的示例代码。 代码似乎运行良好，我正在使用sandbox，因此我可以看到正在转移的付款，所以我不明白为什么我会INVALID.

有人可以看看代码，因为我看不到我做错了什么。

1. basic_payment.php（将付款数据发送给PayPal的文件）

<?php
  require_once ("paypalplatform.php");
  $actionType = "PAY";
  $cancelUrl = "http://[my server details go here]/cancel.php";
  $returnUrl = "http://[my server details go here]/success.php";  
  $currencyCode = "GBP";
  $receiverEmailArray = array( 'seller_15456764326_biz@mail.com' );
  $receiverAmountArray = array( '2' );
  $receiverPrimaryArray = array();
  $senderEmail = "";      
  $feesPayer = "";
  $ipnNotificationUrl = "http://[my server details go here]/ipn.php";
  $memo = "";     
  $pin = "";      
  $preapprovalKey = "";       
  $reverseAllParallelPaymentsOnError = "";        
  $trackingId = generateTrackingID(); 
  $receiverInvoiceIdArray = array( $trackingId );
  $resArray = CallPay ($actionType, $cancelUrl, $returnUrl, $currencyCode, $receiverEmailArray,
                          $receiverAmountArray, $receiverPrimaryArray, $receiverInvoiceIdArray,
                          $feesPayer, $ipnNotificationUrl, $memo, $pin, $preapprovalKey,
                          $reverseAllParallelPaymentsOnError, $senderEmail, $trackingId
  );
  $ack = strtoupper($resArray["responseEnvelope.ack"]);
  if($ack=="SUCCESS")
  {
      if ("" == $preapprovalKey)
      {
          $cmd = "cmd=_ap-payment&paykey=" . urldecode($resArray["payKey"]);
          RedirectToPayPal ( $cmd );
      }
      else
      {
          $payKey = urldecode($resArray["payKey"]);
          $paymentExecStatus = urldecode($resArray["paymentExecStatus"]);
      }
  } 
?>

2. IPN.php（监听贝宝响应的文件）

<?php
    $ipn_post_data = $_POST;
    $url = 'https://www.sandbox.paypal.com/cgi-bin/webscr';
    $request = curl_init();
    curl_setopt_array($request, array
    (
        CURLOPT_URL => $url,
        CURLOPT_POST => TRUE,
        CURLOPT_POSTFIELDS => http_build_query(array('cmd' => '_notify-validate') + $ipn_post_data),
        CURLOPT_RETURNTRANSFER => TRUE,
        CURLOPT_HEADER => FALSE,
    ));
    $response = curl_exec($request);
    $status   = curl_getinfo($request, CURLINFO_HTTP_CODE);
    curl_close($request);
    $to = "oshirowanen@mail.com";
    $from = "me@desktop.com";
    $subject = "response";
    $message = "<pre>".print_r($status,true)." - ".print_r($response,true)."</pre>'n";
    $header = 'To: Oshirowanen <oshirowanen@mail.com>' . "'r'n";
    $header .= 'From: Me <me@desktop.com>' . "'r'n";
    mail($to,$subject,$message,$header);
?>

错误消息：

Apache 错误日志 - 无错误

这就是为什么我在ipn中添加了电子邮件内容.php以尝试捕获某些内容，并且它返回：

<pre>200 - INVALID</pre>

谁能看出我做错了什么？

CURLOPT_SSL_VERIFYPEER => TRUE,
CURLOPT_CAINFO => 'cacert.pem',