diff -urN src.orig/expand.c src/expand.c
--- src.orig/expand.c	2012-10-25 06:37:38.000000000 +0300
+++ src/expand.c	2013-09-10 02:35:00.000000000 +0300
@@ -446,6 +446,9 @@
   { "dnslist_value",       vtype_stringptr,   &dnslist_value },
   { "domain",              vtype_stringptr,   &deliver_domain },
   { "domain_data",         vtype_stringptr,   &deliver_domain_data },
+#ifdef SUPPORT_DSN
+  { "dsn_flag",            vtype_int,         &dsn_flag },
+#endif
   { "exim_gid",            vtype_gid,         &exim_gid },
   { "exim_path",           vtype_stringptr,   &exim_path },
   { "exim_uid",            vtype_uid,         &exim_uid },
diff -urN src.orig/globals.c src/globals.c
--- src.orig/globals.c	2012-10-25 06:37:38.000000000 +0300
+++ src/globals.c	2013-09-10 02:35:30.000000000 +0300
@@ -886,6 +886,9 @@
 int     rcpt_count             = 0;
 int     rcpt_fail_count        = 0;
 int     rcpt_defer_count       = 0;
+#ifdef SUPPORT_DSN
+int     dsn_flag               = 0;
+#endif
 gid_t   real_gid;
 uid_t   real_uid;
 BOOL    really_exim            = TRUE;
diff -urN src.orig/globals.h src/globals.h
--- src.orig/globals.h	2012-10-25 06:37:38.000000000 +0300
+++ src/globals.h	2013-09-10 02:35:56.000000000 +0300
@@ -590,6 +590,9 @@
 extern int     rcpt_count;             /* Count of RCPT commands in a message */
 extern int     rcpt_fail_count;        /* Those that got 5xx */
 extern int     rcpt_defer_count;       /* Those that got 4xx */
+#ifdef SUPPORT_DSN
+extern int     dsn_flag;               /* DSN flag */
+#endif
 extern gid_t   real_gid;               /* Real gid */
 extern uid_t   real_uid;               /* Real user running program */
 extern BOOL    really_exim;            /* FALSE in utilities */
diff -urN src.orig/smtp_in.c src/smtp_in.c
--- src.orig/smtp_in.c	2013-09-10 02:32:45.000000000 +0300
+++ src/smtp_in.c	2013-09-10 02:36:43.000000000 +0300
@@ -1018,6 +1018,9 @@
 recipients_list = NULL;
 rcpt_count = rcpt_defer_count = rcpt_fail_count =
   raw_recipients_count = recipients_count = recipients_list_max = 0;
+#ifdef SUPPORT_DSN
+dsn_flag = 0;
+#endif
 message_linecount = 0;
 message_size = -1;
 acl_added_headers = NULL;
@@ -3640,6 +3643,10 @@
     there may be a delay in this, re-check for a synchronization error
     afterwards, unless pipelining was advertised. */
 
+#ifdef SUPPORT_DSN
+    dsn_flag = flags;
+#endif
+
     if (recipients_discarded) rc = DISCARD; else
       {
       rc = acl_check(ACL_WHERE_RCPT, recipient, acl_smtp_rcpt, &user_msg,