I'm trying to post xml to https URL and getting 500 internal server error in Visual FoxPro https://posgateway.cert.secureexchange.net/Hps.Exchange.PosGateway/PosGatewayService.asmx can you provide a sample code?
A "500 Internal Error" response code means the server-side application code failed for some reason. It is likely the content of the HTTP request body is not to the liking of the server-side. The HTTP request body content is application specific (i.e. it's the application message/payload). I cannot provide sample code because it's impossible for me to know what the application data should be.
Use the http.SessionLogFilename property to log the request/response to a file so you can examine the request headers and body in detail to determine what is likely to cause the server-side code to reject it.