+
+#ifdef EXPERIMENTAL_PROXY
+extern uschar *proxy_host_address; /* IP of host being proxied */
+extern int proxy_host_port; /* Port of host being proxied */
+extern uschar *proxy_required_hosts; /* Hostlist which (require) use proxy protocol */
+extern BOOL proxy_session; /* TRUE if receiving mail from valid proxy */
+extern BOOL proxy_session_failed; /* TRUE if required proxy negotiation failed */
+extern uschar *proxy_target_address; /* IP of proxy server inbound */
+extern int proxy_target_port; /* Port of proxy server inbound */
+#endif
+