Yes, the error indicates that the issue is with the server you are making the request to. The server doesn’t provide a CORS header, so your browser is throwing an error when it makes the request. As you noted, it’s still possible for the server to process the request but the browser will still see the request as failed and thus show an error.
The ‘right’ way to fix this would be to configure the server with the appropriate CORS headers. Alternatively, you could try using the ‘proxy’ flag in your $.post() request.