extern const uschar *process_purpose; /* for debug output */
extern BOOL prod_requires_admin; /* TRUE if prodding requires admin */
-#if defined(SUPPORT_PROXY) || defined(SUPPORT_SOCKS)
+#if defined(SUPPORT_PROXY) || defined(SUPPORT_SOCKS) || defined(EXPERIMENTAL_XCLIENT)
extern uschar *hosts_proxy; /* Hostlist which (require) use proxy protocol */
extern uschar *proxy_external_address; /* IP of remote interface of proxy */
extern int proxy_external_port; /* Port on remote interface of proxy */
extern uschar *uucp_from_sender; /* For building the sender */
extern uschar *warn_message_file; /* Template for warning messages */
-extern uschar *warnmsg_delay; /* String form of delay time */
-extern uschar *warnmsg_recipients; /* Recipients of warning message */
+extern const uschar *warnmsg_delay; /* String form of delay time */
+extern const uschar *warnmsg_recipients; /* Recipients of warning message */
extern BOOL write_rejectlog; /* Control of reject logging */
extern uschar *verify_mode; /* Running a router in verify mode */