extern int strncmpic(const uschar *, const uschar *, int);
extern uschar *strstric(uschar *, uschar *, BOOL);
+#ifdef EXIM_TFO_PROBE
+extern void tfo_probe(void);
+#endif
extern void timesince(struct timeval * diff, struct timeval * then);
extern void tls_modify_variables(tls_support *);
extern uschar *tod_stamp(int);