extern void header_remove(int, const uschar *);
extern BOOL header_testname(header_line *, const uschar *, int, BOOL);
extern BOOL header_testname_incomplete(header_line *, const uschar *, int, BOOL);
extern void header_remove(int, const uschar *);
extern BOOL header_testname(header_line *, const uschar *, int, BOOL);
extern BOOL header_testname_incomplete(header_line *, const uschar *, int, BOOL);
-extern void log_write(unsigned int, int, const char *format, ...);
+extern void log_write(unsigned int, int, const char *format, ...) PRINTF_FUNCTION(3,4);
extern int lss_b64decode(uschar *, uschar **);
extern uschar *lss_b64encode(uschar *, int);
extern int lss_match_domain(uschar *, uschar *);
extern int lss_b64decode(uschar *, uschar **);
extern uschar *lss_b64encode(uschar *, int);
extern int lss_match_domain(uschar *, uschar *);
extern void smtp_vprintf(const char *, va_list);
extern uschar *string_copy(uschar *);
extern uschar *string_copyn(uschar *, int);
extern void smtp_vprintf(const char *, va_list);
extern uschar *string_copy(uschar *);
extern uschar *string_copyn(uschar *, int);