extern int string_datestamp_type; /* After insertion by string_format */
extern BOOL strip_excess_angle_brackets; /* Surrounding route-addrs */
extern BOOL strip_trailing_dot; /* Remove dots at ends of domains */
-extern uschar *submission_domain; /* Domain for submission mode */
-extern uschar *submission_name; /* User name set from ACL */
+extern const uschar *submission_domain;/* Domain for submission mode */
+extern const uschar *submission_name; /* User name set from ACL */
extern BOOL syslog_duplication; /* FALSE => no duplicate logging */
extern int syslog_facility; /* As defined by Syslog.h */
extern BOOL syslog_pid; /* TRUE if PID on syslogs */