Hello Ade,
I just realised now that, you are right, the HTTPClient doesn't need update at the moment. I follow the calculator sample feedback idea, it show error too, although I have tested it on another server and the still dispaly.
The Calculator sample ONLY shown that error if the server side response status code is 500. And this only happend if the PHP "mail" function doesn't work as expected. If you receive such error some times, then you know the cause of the error: the "mail" function doens't work as expected. In any other case you can receive that error with the Calculator sample: at least using the provided PHP script.
And this last is the important question... are you modified the PHP script? How? Are you modified the Calculator feedback related code? And how? Take a look at the PHP script that we are talking about, just like is placed right now in my hosting and you can found in the Calculator sample inside the "Server" directory:
Can you see that we only answer with a "500" status code if the "mail" function doesn't work as expected? Now take a look at the HttpClient Error event used in the Calculator sample Comments view:
Can you see that we only shown the "error" message if the status code is "500"? Then the Calculator sample works as expected, and only shown that "error" if the server side return an status code "500". Never in other case.