How to handle a ESP8266 webserver only to the access point? I'm developing a application that needs to be somewhat secure, so to configure the parameters it handles a GPIO interrupt (from a button) to open a server, that lets you configure it. The problem is that it is configured to send an email, so it is connected to the wifi.

With this in mind, I need to detect the source of the connection so I can serve the html only to the access point connections. 

Is it possible?
It is not documented, but you can construct WiFiServer or ESP8266WebServer with IP address. If you use the IP address of the AP, the server will be available only on the SoftAP. If you use the IP address of the station, the server will be available only on STA interface.

#include &lt;ESP8266WiFi.h&gt;

WiFiServer telneServer(23);

void setup() {
  ...
  telneServer = WiFiServer(WiFi.softAPIP(), 23);
//  telneServer = WiFiServer(WiFi.localIP(), 23);
  telneServer.begin();