extern uschar *smtp_ratelimit_rcpt; /* Parameters for RCPT limiting */
extern uschar *smtp_read_error; /* Message for SMTP input error */
extern int smtp_receive_timeout; /* Applies to each received line */
+extern uschar *smtp_receive_timeout_s; /* ... expandable version */
extern uschar *smtp_reserve_hosts; /* Hosts for reserved slots */
extern BOOL smtp_return_error_details; /* TRUE to return full info */
extern int smtp_rlm_base; /* Base interval for MAIL rate limit */