CORS not working while passing data via POST form fields

Question

I'm creating simple API using coldfusion taffy framework. I've enabled the CORS in my app settings even though I'm getting a "CORS preflight channel did not succeed" issue while calling the POST method.

But I found something it's strange to me. When I call the POST method by passing the data via URL. For example like this, it's working fine without issues

http://sample.com/api/cont/?attributes={'name':'test','email':'test@gmail.com','cpInfo':null,'phone':'sample','companyName':'company','comments':'I%27ve+tested+the+cors+domain.com'}&functionName=doContactSales

When I call the same POST method by passing the data in form fields. I'm getting this issues "CORS preflight channel did not succeed"

http: //sample.com/api/cont/

attributes='name':'test','email':'test@gmail.com','cpInfo':null,'phone':'sample','companyName':'company','comments':'I%27ve+tested+the+cors+domain.com'}

functionName=doContactSales

I've added these headers in the response.

response.setHeader("Access-Control-Allow-Origin","http://www.sample.com" );
response.setHeader("Access-Control-Allow-Methods", "#verb#, OPTIONS" );
response.setHeader("Access-Control-Allow-Headers", "accept, Origin, application/json, X-Requested-With, Content-Type, Access-Control-Allow-Origin" );               
response.setHeader("Access-Control-Max-Age", "86400" );

Please let me know Why I'm getting "CORS preflight channel did not succeed" on passing the data via form fields. And how to fix it out.