- phpmail的应用函数fsockopen()位置：..\vendor\pear\net_socket\Net\Socket.php 约156行：
$openfunc = $this->persistent ? 'fsockopen' : 'fsockopen';
$errno = 0;
$errstr = ;
$old_track_errors = @ini_set('track_errors', 1);
if ($timeout <= 0) {
$timeout = @ini_get('default_socket_timeout');
}
if ($options && function_exists('stream_context_create')) {
$context = stream_context_create($options);
// Since PHP 5 fsockopen doesn't allow context specification
if (function_exists('stream_socket_client')) {
$flags = STREAM_CLIENT_CONNECT;
