You should post API Key with request. API key should provide in Request Body.
URL : http://kanbanize.com/index.php/api/kanbanize/login/email/test1%40gmail.com/pass/test1
You must add API Key
To authenticate yourself to the system, you need to specify the API key as a header. To generate such a key, login to the system and go to the My account->API panel. If your role allows it, you will be able to access the tab and generate a unique key.
Note: Header name must be "apikey".
Go Through this Page for more info : https://kanbanize.com/ctrl_integration
Now check are you able to connect that URL from that PC where you running the exe.
IF Yes : Then check 1. Proxy required or not any firewall is there or not
To Compare where its stuck you can use Fiddler : http://www.telerik.com/fiddler
And compare two request using browser and using Exe