生产服务器:URL未打开

URL是正确的，发送的参数被确认在开发服务器上工作，但在生产服务器上不断返回错误。

$url  = "http://www.smslive247.com/http/index.aspx?";
$url .= "cmd=sendquickmsg";
$url .= "&owneremail=".urlencode($owenerEmail);
$url .= "&subacct=".urlencode($subAcct);
$url .= "&subacctpwd=".urlencode($subPwd);
$url .= "&message=".urlencode($msg);
$url .= "&sender=".urlencode($sender);
$url .= "&sendto=".urlencode($phone);
$url .= "&msgtype=0";
if($f = @fopen($url, "r")){
    echo "Successful.";
}else{
    echo $url." Error: URL could not be opened.";
}

当我试图返回URL并将其放在浏览器上时，它会返回Success消息。我该怎么办？