+#ifdef EXPERIMENTAL_DBL
+extern int dbl_defer_errno; /* error number set when a remote delivery is deferred with a host error */
+extern uschar *dbl_defer_errstr; /* error string set when a remote delivery is deferred with a host error */
+extern uschar *dbl_delivery_query; /* query string to log delivery info in DB */
+extern uschar *dbl_delivery_ip; /* IP of host, which has accepted delivery */
+extern int dbl_delivery_port; /* port of host, which has accepted delivery */
+extern uschar *dbl_delivery_fqdn; /* FQDN of host, which has accepted delivery */
+extern uschar *dbl_delivery_local_part;/* local part of address being delivered */
+extern uschar *dbl_delivery_domain; /* domain part of address being delivered */
+extern uschar *dbl_delivery_confirmation; /* SMTP confirmation message */
+#endif
+