Wordpress wp_remote_post
You will need to enable cURL in your php.ini file.
wp_remote_post() uses a class called WP_Http that in turn can use one of three transport classes (see file class-http.php function _get_first_available_transport).
POST method will work with class WP_Http_Curl, but will not work with class WP_Http_Streams (the cURL fallback).
The alternative is to use wp_remote_get()