How to do a simple POST in REST?

implement_post_contact

Here's my script:
POST /livex/api/contact_form HTTP/1.1
Host: local.testdrupal.com
Content-Type: application/hal+json
Authorization: Basic bGl2ZXg6MTM1NzkwLi4=
Cache-Control: no-cache
Postman-Token: 1b64499c-5091-588e-f72e-e2202dc066b6

{
   "_links": {
      "type": {
        "href":"http://local.testdrupal.com/rest/type/api/contact"
      }
   },
   "name":[
     {
       "value": "Eduardo"
     }
   ],
    "mail":[
     {
       "value": "[email protected]"
     }
   ],
    "subject":[
     {
       "value": "Testing Post Contact"
     }
   ],
   "message":[
     {
       "value": "New Mail"
     }
   ]
}