path: root/mail-mta/exim/files/exim_482_dsn_1_3.patch

Modified for 4.82 by Gentoo -- not the official patch from
http://sourceforge.net/projects/eximdsn/

diff -Naur exim-4.82_RC5.orig/README.DSN exim-4.82_RC5/README.DSN
--- exim-4.82_RC5.orig/README.DSN	1970-01-01 01:00:00.000000000 +0100
+++ exim-4.82_RC5/README.DSN	2013-10-27 21:47:32.000000000 +0100
@@ -0,0 +1,118 @@
+Exim DSN Patch (4.76)
+---------------------
+
+This patch is free software; you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation; either version 2 of the License, or
+(at your option) any later version.
+
+This patch is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with this patch; if not, write to the Free Software
+Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111 USA.
+
+Install
+-------
+cd into the source tree for a vanilla exim
+
+patch -p1 </path/to/patch/file.patch
+
+Example :-
+[root@linuxbuild exim-4.72-test]# patch -p1 <../exim.dsn.patch-472
+
+Expected Output :-
+patching file README.DSN
+patching file src/config.h.defaults
+patching file src/deliver.c
+patching file src/exim.c
+patching file src/exim.h
+patching file src/globals.c
+patching file src/globals.h
+patching file src/local_scan.h
+patching file src/macros.h
+patching file src/readconf.c
+patching file src/route.c
+patching file src/smtp_in.c
+patching file src/spool_in.c
+patching file src/spool_out.c
+patching file src/structs.h
+patching file src/transport.c
+patching file src/transports/smtp.c
+
+
+This patch can be included / excluded from the compilation by use of the #define SUPPORT_DSN
+which gets added into src/config.h.defaults & src/EDITME by the patch.
+
+Use
+---
+
+The facility (once compiled in) can be turned on for a particular router via the
+dsn_process directive Eg :-
+
+dest_delivery_int:
+  driver = manualroute
+  domains = +relay_to_domains
+  condition = ${if eq {${lc:$sender_address_domain}}\
+                                 {domain.com}\
+                                 {yes}{no}\
+                       }
+  dsn_process
+  hide route_data = ${lc:${extract{mailHost}{$address_data}{$value}{}}}
+  transport = remote_smtp
+
+Exim will produce 1 of 2 DSN's back to the originator, or pass on the DSN request.
+The 2 DSN's will either contain (relayed via non "Remote SMTP" router) or
+(relayed to non-DSN-aware mailer) depending on if the delivery was VIA an SMTP
+transport or not.
+
+
+Credits
+-------
+
+The original work for the patch was done by Philip Hazel in Exim 3
+
+The extract was taken and re-applied to Exim 4 by the following :-
+Phil Bingham   (phil.bingham@cwipapps.net)
+Steve Falla    (steve.falla@cwipapps.net)
+Ray Edah       (ray.edah@cwipapps.net)
+Andrew Johnson (andrew.johnson@cwippaps.net)
+Adrian Hungate (adrian.hungate@cwipapps.net)
+
+Now Primarily maintained by :-
+Andrew Johnson (andrew.johnson@cwippaps.net)
+
+Contributions
+-------------
+Andrey J. Melnikoff (TEMHOTA) (temnota@kmv.ru) 
+
+
+ChangeLog
+---------
+
+14-Apr-2006 : Changed subject to "Delivery Status Notification"
+
+17-May-2006 : debug_printf in spool-in.c were not wrapped with #ifndef COMPILE_UTILITY
+              thanks to Andrey J. Melnikoff for this information
+
+12-Sep-2006 : Now supports Exim 4.63
+
+12-Sep-2006 : src/EDITME did not include the #define SUPPORT_DSN as stated
+              in the documentation, this has now been corrected
+              thanks to Robert Kehl for this information
+
+28-Jul-2008 : New version for exim 4.69 released.
+
+02-Jul-2010 : New version for exim 4.72 released.
+
+20-May-2011 : New version for exim 4.76 released.
+
+
+Support for this patch (limited though it is) will only be provided through the SourceForge
+project page (http://sourceforge.net/projects/eximdsn/)
+
+--
+Andrew Johnson Cable & Wireless
diff -Naur exim-4.82_RC5.orig/src/config.h.defaults exim-4.82_RC5/src/config.h.defaults
--- exim-4.82_RC5.orig/src/config.h.defaults	2013-10-27 21:46:25.000000000 +0100
+++ exim-4.82_RC5/src/config.h.defaults	2013-10-27 21:47:32.000000000 +0100
@@ -136,6 +136,7 @@
 #define SUPPORT_MOVE_FROZEN_MESSAGES
 #define SUPPORT_PAM
 #define SUPPORT_TLS
+#define SUPPORT_DSN
 #define SUPPORT_TRANSLATE_IP_ADDRESS
 
 #define SYSLOG_LOG_PID
diff -Naur exim-4.82_RC5.orig/src/deliver.c exim-4.82_RC5/src/deliver.c
--- exim-4.82_RC5.orig/src/deliver.c	2013-10-27 21:46:25.000000000 +0100
+++ exim-4.82_RC5/src/deliver.c	2013-10-27 21:47:32.000000000 +0100
@@ -63,6 +63,9 @@
 static address_item *addr_remote = NULL;
 static address_item *addr_route = NULL;
 static address_item *addr_succeed = NULL;
+#ifdef SUPPORT_DSN
+static address_item *addr_dsntmp = NULL;
+#endif
 
 static FILE *message_log = NULL;
 static BOOL update_spool;
@@ -2966,6 +2969,15 @@
       addr->flags |= af_prdr_used; break;
 #endif
 
+    #ifdef SUPPORT_DSN
+    case 'D':
+    if (addr == NULL) break;
+    addr->dsn_aware = (*ptr)? string_copy(ptr) : string_copy(" ");
+    while (*ptr++);
+    DEBUG(D_deliver) debug_printf("DSN read: addr->dsn_aware = %s\n", addr->dsn_aware);
+    break;
+    #endif
+
     case 'A':
     if (addr == NULL)
       {
@@ -4074,6 +4086,15 @@
       if (addr->flags & af_prdr_used) rmt_dlv_checked_write(fd, "P", 1);
       #endif
 
+      #ifdef SUPPORT_DSN
+      if (addr->dsn_aware == NULL)
+        addr->dsn_aware = string_copy(" ");
+      DEBUG(D_deliver) debug_printf("DSN write: addr->dsn_aware = %s\n", addr->dsn_aware);     
+      sprintf(big_buffer, "D%s", addr->dsn_aware);
+      DEBUG(D_deliver) debug_printf("DSN write: big_buffer = %s (%d)\n", big_buffer, strlen(big_buffer)+1);
+      write(fd, big_buffer, strlen(big_buffer)+1);
+      #endif
+
       /* Retry information: for most success cases this will be null. */
 
       for (r = addr->retries; r != NULL; r = r->next)
@@ -5219,6 +5240,14 @@
       if (r->pno >= 0)
         new->onetime_parent = recipients_list[r->pno].address;
 
+      #ifdef SUPPORT_DSN
+      /* If DSN support is enabled, set the dsn flags and the original receipt 
+         to be passed on to other DSN enabled MTAs */
+      new->dsn_flags = r->dsn_flags & rf_dsnflags;
+      new->dsn_orcpt = r->orcpt;
+      debug_printf("DSN (deliver): orcpt: %s  flags: %d\n", new->dsn_orcpt, new->dsn_flags);	 
+      #endif
+
       switch (process_recipients)
         {
         /* RECIP_DEFER is set when a system filter freezes a message. */
@@ -6163,6 +6192,12 @@
     regex_must_compile(US"\\n250[\\s\\-]PRDR(\\s|\\n|$)", FALSE, TRUE);
   #endif
 
+  #ifdef SUPPORT_DSN
+  /* Set the regex to check for DSN support on remote MTA */
+  if (regex_DSN == NULL) regex_DSN  =
+    regex_must_compile(US"\\n250[\\s\\-]DSN(\\s|\\n|$)", FALSE, TRUE);
+  #endif
+
   /* Now sort the addresses if required, and do the deliveries. The yield of
   do_remote_deliveries is FALSE when mua_wrapper is set and all addresses
   cannot be delivered in one transaction. */
@@ -6267,6 +6302,179 @@
 
 else if (!dont_deliver) retry_update(&addr_defer, &addr_failed, &addr_succeed);
 
+#ifdef SUPPORT_DSN
+/* ********** philb - Send DSN for successful messages */
+
+addr_dsntmp = addr_succeed;
+
+while(addr_dsntmp != NULL)
+{
+   BOOL dsn_sendmessage = FALSE;
+   uschar dsnmsgbuf[4096];
+ 
+   DEBUG(D_deliver)
+      debug_printf("DSN: processing router : %s\n", addr_dsntmp->router->name);
+
+   DEBUG(D_deliver)
+      debug_printf("DSN: processing successful delivery address: %s\n", addr_dsntmp->address);
+  
+   if (testflag(addr_dsntmp, af_ignore_error))
+   {   
+      DEBUG(D_deliver)
+         debug_printf("DSN: Ignore error for: %s\n", addr_dsntmp->address);
+   }
+   else
+   {
+     DEBUG(D_deliver) debug_printf("DSN: Checking Flag\n");	 
+     if (addr_dsntmp->dsn_aware == NULL) {
+         DEBUG(D_deliver) debug_printf("DSN: dsn_aware was NULL, setting to space at %s %d\n", __FILE__, __LINE__);
+         addr_dsntmp->dsn_aware = string_copy(" ");
+     }
+     DEBUG(D_deliver) debug_printf("DSN: Sender_address: %s\n", sender_address);	 
+     DEBUG(D_deliver) debug_printf("DSN: orcpt: %s  flags: %d\n", addr_dsntmp->dsn_orcpt, addr_dsntmp->dsn_flags);	 
+     DEBUG(D_deliver) debug_printf("DSN: envid: %s  ret: %d\n", dsn_envid, dsn_ret);	 
+     DEBUG(D_deliver) debug_printf("DSN: Remote SMTP server supports DSN: %s\n", addr_dsntmp->dsn_aware);	 
+      	
+      /* Process the flags */
+     if((addr_dsntmp->dsn_flags & rf_dsnflags) != 0) 
+     {
+         /* We've got at least one flag set */
+
+	 /* set flag so we don't send bounces */
+	 setflag(addr_dsntmp, af_ignore_error);
+
+	 if((addr_dsntmp->dsn_flags & rf_notify_never) != 0)
+         {
+            DEBUG(D_deliver) debug_printf("DSN: NEVER FLAG\n");
+
+            /* nothing to do here */
+         }
+         
+         if((addr_dsntmp->dsn_flags & rf_notify_success) != 0)
+         {
+            DEBUG(D_deliver) debug_printf("DSN: SUCCESS FLAG\n");
+
+            dsn_sendmessage = TRUE;
+         }
+
+         if((addr_dsntmp->dsn_flags & rf_notify_failure) != 0)
+         {
+            DEBUG(D_deliver) debug_printf("DSN: FAILURE FLAG\n");
+
+            /* allow bounce messages */
+            clearflag(addr_dsntmp, af_ignore_error);
+         }
+
+         if((addr_dsntmp->dsn_flags & rf_notify_delay) != 0)
+         {
+            DEBUG(D_deliver) debug_printf("DSN: DELAY FLAG\n");
+
+            /* hmm, what to do here? */
+         }
+      }
+
+      if ((addr_dsntmp->dsn_aware != 0) && (addr_dsntmp->dsn_aware[0] != 'Y') && (dsn_sendmessage == TRUE) && (addr_dsntmp->router->dsn_process == TRUE))
+      {
+         pid_t pid;
+         int fd;
+      
+	 /* remote MTA does not support DSN, so we need to send message */
+	 
+	 /* create exim process to send message */ 	 
+	 pid = child_open_exim(&fd);
+
+         DEBUG(D_deliver) debug_printf("DSN: child_open_exim returns: %d\n", pid);
+	 
+	 if (pid < 0)  /* Creation of child failed */
+	 {
+	    log_write(0, LOG_MAIN|LOG_PANIC_DIE, "Process %d (parent %d) failed to "
+               "create child process to send failure message: %s", getpid(),
+               getppid(), strerror(errno));
+
+             DEBUG(D_deliver) debug_printf("DSN: child_open_exim failed\n");
+
+         }	 
+	 else  /* Creation of child succeeded */
+	 {
+           FILE *f = fdopen(fd, "wb");
+	   int topt = topt_add_return_path;
+	   uschar boundaryStr[64];
+	   
+           DEBUG(D_deliver) debug_printf("sending error message to: %s\n", sender_address);
+      
+           /* build unique id for MIME boundary */
+           snprintf(boundaryStr, 63, "%d-cwdsn-%d", pid, rand());      
+           DEBUG(D_deliver) debug_printf("DSN: MIME boundary: %s\n", boundaryStr);
+      
+           /* if the sender doesn't want the whole message returned, don't send the body */
+           if (dsn_ret != dsn_ret_full) topt |= topt_no_body;
+      
+           if (errors_reply_to != NULL) fprintf(f,"Reply-To: %s\n", errors_reply_to);
+     
+	   fprintf(f,"Auto-Submitted: auto-generated\n");
+	   fprintf(f,"From: Mail Delivery System <Mailer-Daemon@%s>\n", qualify_domain_sender);
+	   fprintf(f,"To: %s\n", sender_address);
+	   fprintf(f,"Subject: Delivery Status Notification\n");
+	   fprintf(f,"Content-Type: multipart/report; report-type=delivery-status; boundary=%s\n", boundaryStr);
+           fprintf(f,"MIME-Version: 1.0\n\n");
+
+           fprintf(f,"--%s\n", boundaryStr);
+	   fprintf(f,"Content-type: text/plain; charset=us-ascii\n\n");
+	   
+	   fprintf(f,"This message was created automatically by mail delivery software.\n");
+	   fprintf(f," ----- The following addresses had successful delivery notifications -----\n");
+/* AH: added specific message for non "Remote SMTP" situations */
+           if (addr_dsntmp->dsn_aware[0] == 'N') {
+	     fprintf(f,"<%s> (relayed to non-DSN-aware mailer)\n\n", addr_dsntmp->address);
+           } else {
+	     fprintf(f,"<%s> (relayed via non \"Remote SMTP\" router)\n\n", addr_dsntmp->address);
+           }
+
+	   fprintf(f,"--%s\n", boundaryStr);
+	   fprintf(f,"Content-type: message/delivery-status\n\n");
+	   
+           if (dsn_envid) { /* Test for NULL added by GC */
+               fprintf(f,"Original-Envelope-Id: %s\n", dsn_envid);
+           }
+	   fprintf(f,"Reporting-MTA: dns; %s\n", qualify_domain_sender);
+           if (addr_dsntmp->dsn_orcpt) { /* Test for NULL added by GC */
+               fprintf(f,"Original-Recipient: %s\n", addr_dsntmp->dsn_orcpt);
+           }
+	   fprintf(f,"Action: delivered\n\n");
+	   
+	   fprintf(f,"--%s\n", boundaryStr);
+	   fprintf(f,"Content-type: message/rfc822\n\n");
+	   
+	   fflush(f);
+	   transport_filter_argv = NULL;   /* Just in case */
+           return_path = sender_address;   /* In case not previously set */
+	   
+	   /* Write the original email out */
+	   transport_write_message(NULL, fileno(f), topt, 2048, NULL, NULL, NULL, NULL, NULL, 0);	   
+	   fflush(f);
+	      
+	   fprintf(f,"\n");	   
+	   fprintf(f,"--%s--\n", boundaryStr);
+	   
+	   fflush(f);	   	   
+	   fclose(f);
+           rc = child_close(pid, 0);     /* Waits for child to close, no timeout */
+	}
+      }
+      else
+      {  if (addr_dsntmp->router->dsn_process == TRUE)
+	 DEBUG(D_deliver) debug_printf("DSN: *** NOT SENDING DSN SUCCESS Message ***\n"); 
+         if (addr_dsntmp->router->dsn_process == FALSE)
+	 DEBUG(D_deliver) debug_printf("DSN: *** NOT SENDING DSN SUCCESS Message (gagged) ***\n"); 
+      }
+   }
+
+   addr_dsntmp = addr_dsntmp->next;
+}
+
+/* ********** philb - end of mod */
+#endif
+
 /* If any addresses failed, we must send a message to somebody, unless
 af_ignore_error is set, in which case no action is taken. It is possible for
 several messages to get sent if there are addresses with different
diff -Naur exim-4.82_RC5.orig/src/EDITME exim-4.82_RC5/src/EDITME
--- exim-4.82_RC5.orig/src/EDITME	2013-10-27 21:46:25.000000000 +0100
+++ exim-4.82_RC5/src/EDITME	2013-10-27 21:47:32.000000000 +0100
@@ -192,6 +192,8 @@
 # least one type of lookup. You should consider whether you want to build
 # the Exim monitor or not.
 
+# Support DSN
+SUPPORT_DSN=yes
 
 #------------------------------------------------------------------------------
 # These settings determine which individual router drivers are included in the
diff -Naur exim-4.82_RC5.orig/src/exim.c exim-4.82_RC5/src/exim.c
--- exim-4.82_RC5.orig/src/exim.c	2013-10-27 21:46:25.000000000 +0100
+++ exim-4.82_RC5/src/exim.c	2013-10-27 21:47:32.000000000 +0100
@@ -831,6 +831,9 @@
 #ifdef EXPERIMENTAL_REDIS
   fprintf(f, " Experimental_Redis");
 #endif
+#ifdef SUPPORT_DSN
+  fprintf(f, " C&W_DSN_1.3");
+#endif
 fprintf(f, "\n");
 
 fprintf(f, "Lookups (built-in):");
@@ -2653,6 +2656,16 @@
       break;
       }
 
+    #ifdef SUPPORT_DSN
+    /* -MCD: set the smtp_use_dsn flag; this indicates that the host
+       that exim is connected to supports the esmtp extension DSN */
+    else if (strcmp(argrest, "CD") == 0)
+      {
+      smtp_use_dsn = TRUE;
+      break;
+      }
+    #endif
+
     /* -MCP: set the smtp_use_pipelining flag; this is useful only when
     it preceded -MC (see above) */
 
diff -Naur exim-4.82_RC5.orig/src/globals.c exim-4.82_RC5/src/globals.c
--- exim-4.82_RC5.orig/src/globals.c	2013-10-27 21:46:25.000000000 +0100
+++ exim-4.82_RC5/src/globals.c	2013-10-27 21:47:32.000000000 +0100
@@ -124,6 +124,13 @@
 uschar *local_scan_path        = NULL;
 #endif
 
+#ifdef SUPPORT_DSN
+BOOL   dsn                    = TRUE;
+uschar  *dsn_envid            = NULL;
+int    dsn_ret                = 0;
+const pcre  *regex_DSN        = NULL;
+BOOL   smtp_use_dsn           = FALSE;
+#endif
 
 #ifdef SUPPORT_TLS
 BOOL    gnutls_compat_mode     = FALSE;
@@ -341,6 +348,11 @@
   NULL,			/* authenticator */
   NULL,			/* auth_id */
   NULL,			/* auth_sndr */
+  #ifdef SUPPORT_DSN
+  NULL,                 /* dsn_orcpt */
+  0,                    /* dsn_flags */
+  NULL,                 /* dsn_aware */
+  #endif
   (uid_t)(-1),          /* uid */
   (gid_t)(-1),          /* gid */
   0,                    /* flags */
@@ -1096,6 +1108,9 @@
     TRUE,                      /* verify_sender */
     FALSE,                     /* uid_set */
     FALSE,                     /* unseen */
+#ifdef SUPPORT_DSN
+    FALSE,                     /* dsn_process */
+#endif
 
     self_freeze,               /* self_code */
     (uid_t)(-1),               /* uid */
@@ -1105,6 +1120,7 @@
     NULL,                      /* transport instance */
     NULL,                      /* pass_router */
     NULL                       /* redirect_router */
+
 };
 
 uschar *router_name            = NULL;
diff -Naur exim-4.82_RC5.orig/src/globals.h exim-4.82_RC5/src/globals.h
--- exim-4.82_RC5.orig/src/globals.h	2013-10-27 21:46:25.000000000 +0100
+++ exim-4.82_RC5/src/globals.h	2013-10-27 21:47:32.000000000 +0100
@@ -130,6 +130,13 @@
 extern int (*receive_ferror)(void);
 extern BOOL (*receive_smtp_buffered)(void);
 
+#ifdef SUPPORT_DSN
+extern BOOL   dsn;                    /* FALSE if DSN not to be used */
+extern uschar  *dsn_envid;            /* DSN envid string */
+extern int    dsn_ret;                /* DSN ret type*/
+extern const pcre  *regex_DSN;        /* For recognizing DSN settings */
+extern BOOL   smtp_use_dsn;           /* Global for passed connections */
+#endif
 
 /* For clearing, saving, restoring address expansion variables. We have to have
 the size of this vector set explicitly, because it is referenced from more than
diff -Naur exim-4.82_RC5.orig/src/local_scan.h exim-4.82_RC5/src/local_scan.h
--- exim-4.82_RC5.orig/src/local_scan.h	2013-10-27 21:46:25.000000000 +0100
+++ exim-4.82_RC5/src/local_scan.h	2013-10-27 21:47:32.000000000 +0100
@@ -124,9 +124,13 @@
 field is always NULL except for one_time aliases that had errors_to on the
 routers that generated them. */
 
+/* Added the dsn attributes orcpt and dsn_flags for DSN support*/
+
 typedef struct recipient_item {
   uschar *address;              /* the recipient address */
   int     pno;                  /* parent number for "one_time" alias, or -1 */
+  uschar *orcpt;                /* DSN orcpt */
+  int    dsn_flags;             /* DSN flags */
   uschar *errors_to;            /* the errors_to address or NULL */
 #ifdef EXPERIMENTAL_BRIGHTMAIL
   uschar *bmi_optin;
diff -Naur exim-4.82_RC5.orig/src/macros.h exim-4.82_RC5/src/macros.h
--- exim-4.82_RC5.orig/src/macros.h	2013-10-27 21:46:25.000000000 +0100
+++ exim-4.82_RC5/src/macros.h	2013-10-27 21:47:32.000000000 +0100
@@ -778,6 +778,22 @@
 #define topt_no_body            0x040  /* Omit body */
 #define topt_escape_headers     0x080  /* Apply escape check to headers */
 
+ /* Flags for recipient_block, used in DSN support */
+
+ #define rf_onetime              0x01  /* A one-time alias */
+ #define rf_notify_never         0x02  /* NOTIFY= settings */
+ #define rf_notify_success       0x04
+ #define rf_notify_failure       0x08
+ #define rf_notify_delay         0x10
+
+ #define rf_dsnflags  (rf_notify_never | rf_notify_success | \
+                       rf_notify_failure | rf_notify_delay)
+
+ /* DSN RET types */
+
+ #define dsn_ret_full            1
+ #define dsn_ret_hdrs            2
+
 /* Codes for the host_find_failed and host_all_ignored options. */
 
 #define hff_freeze   0
diff -Naur exim-4.82_RC5.orig/src/readconf.c exim-4.82_RC5/src/readconf.c
--- exim-4.82_RC5.orig/src/readconf.c	2013-10-27 21:46:25.000000000 +0100
+++ exim-4.82_RC5/src/readconf.c	2013-10-27 21:49:15.000000000 +0100
@@ -229,6 +229,9 @@
  /* This option is now a no-op, retained for compability */
   { "drop_cr",                  opt_bool,        &drop_cr },
 /*********************************************************/
+#ifdef SUPPORT_DSN
+  { "dsn",                      opt_bool,        &dsn },
+#endif
   { "dsn_from",                 opt_stringptr,   &dsn_from },
   { "envelope_to_remove",       opt_bool,        &envelope_to_remove },
   { "errors_copy",              opt_stringptr,   &errors_copy },
diff -Naur exim-4.82_RC5.orig/src/receive.c exim-4.82_RC5/src/receive.c
--- exim-4.82_RC5.orig/src/receive.c	2013-10-27 21:46:25.000000000 +0100
+++ exim-4.82_RC5/src/receive.c	2013-10-27 21:47:32.000000000 +0100
@@ -490,6 +490,8 @@
     memcpy(recipients_list, oldlist, oldmax * sizeof(recipient_item));
   }
 
+/* memset added by GC to blank dsn records, etc. */
+memset(&recipients_list[recipients_count], 0, sizeof(recipient_item));
 recipients_list[recipients_count].address = recipient;
 recipients_list[recipients_count].pno = pno;
 #ifdef EXPERIMENTAL_BRIGHTMAIL
diff -Naur exim-4.82_RC5.orig/src/route.c exim-4.82_RC5/src/route.c
--- exim-4.82_RC5.orig/src/route.c	2013-10-27 21:46:25.000000000 +0100
+++ exim-4.82_RC5/src/route.c	2013-10-27 21:47:32.000000000 +0100
@@ -58,6 +58,10 @@
                  (void *)offsetof(router_instance, domains) },
   { "driver",             opt_stringptr|opt_public,
                  (void *)offsetof(router_instance, driver_name) },
+  #ifdef SUPPORT_DSN
+  { "dsn_process",        opt_bool|opt_public,
+                 (void *)offsetof(router_instance, dsn_process) },
+  #endif
   { "errors_to",          opt_stringptr|opt_public,
                  (void *)(offsetof(router_instance, errors_to)) },
   { "expn",               opt_bool|opt_public,
@@ -270,6 +274,13 @@
 
   if (r->pass_router_name != NULL)
     set_router(r, r->pass_router_name, &(r->pass_router), TRUE);
+
+  #ifdef SUPPORT_DSN
+    if (r->dsn_process == FALSE)
+      DEBUG(D_route) debug_printf("%s router skipping DSN - add dsn_process to router\n", r->name);
+    if (r->dsn_process == TRUE)
+      DEBUG(D_route) debug_printf("%s router performing DSN \n", r->name);
+  #endif
   }
 }
 
@@ -1412,7 +1423,10 @@
 
 copyflag(new, addr, af_propagate);
 new->p.address_data = addr->p.address_data;
-
+#ifdef SUPPORT_DSN
+  new->dsn_flags = addr->dsn_flags;
+  new->dsn_orcpt = addr->dsn_orcpt;
+#endif
 
 /* As it has turned out, we haven't set headers_add or headers_remove for the
  * clone. Thinking about it, it isn't entirely clear whether they should be
diff -Naur exim-4.82_RC5.orig/src/smtp_in.c exim-4.82_RC5/src/smtp_in.c
--- exim-4.82_RC5.orig/src/smtp_in.c	2013-10-27 21:46:25.000000000 +0100
+++ exim-4.82_RC5/src/smtp_in.c	2013-10-27 21:47:32.000000000 +0100
@@ -213,6 +213,9 @@
 #ifdef EXPERIMENTAL_PRDR
   ENV_MAIL_OPT_PRDR,
 #endif
+#ifdef SUPPORT_DSN
+  ENV_MAIL_OPT_RET, ENV_MAIL_OPT_ENVID,
+#endif
   ENV_MAIL_OPT_NULL
   };
 typedef struct {
@@ -228,6 +231,10 @@
 #ifdef EXPERIMENTAL_PRDR
     { US"PRDR",   ENV_MAIL_OPT_PRDR,   FALSE },
 #endif
+#ifdef SUPPORT_DSN
+    { US"RET",    ENV_MAIL_OPT_RET,    FALSE },
+    { US"ENVID",  ENV_MAIL_OPT_ENVID,  FALSE },
+#endif
     { US"NULL",   ENV_MAIL_OPT_NULL,   FALSE }
   };
 
@@ -1073,6 +1080,13 @@
 sender_verified_list = NULL;        /* No senders verified */
 memset(sender_address_cache, 0, sizeof(sender_address_cache));
 memset(sender_domain_cache, 0, sizeof(sender_domain_cache));
+
+#ifdef SUPPORT_DSN
+/* Reset the DSN flags */
+dsn_ret = 0;
+dsn_envid = NULL;
+#endif
+
 authenticated_sender = NULL;
 #ifdef EXPERIMENTAL_BRIGHTMAIL
 bmi_run = 0;
@@ -2679,6 +2693,10 @@
   int ptr, size, rc;
   int c, i;
   auth_instance *au;
+#ifdef SUPPORT_DSN
+  uschar *orcpt = NULL;
+  int flags;
+#endif
 
   switch(smtp_read_command(TRUE))
     {
@@ -3106,6 +3124,12 @@
         s = string_cat(s, &size, &ptr, US"-8BITMIME\r\n", 11);
         }
 
+      #ifdef SUPPORT_DSN
+      /* Advertise DSN support if configured to do so. */
+      if (dsn) 
+        s = string_cat(s, &size, &ptr, US"250-DSN\r\n", 9);
+      #endif
+
       /* Advertise ETRN if there's an ACL checking whether a host is
       permitted to issue it; a check is made when any host actually tries. */
 
@@ -3360,6 +3384,42 @@
           arg_error = TRUE;
           break;
 
+#ifdef SUPPORT_DSN
+
+        /* Handle the two DSN options, but only if configured to do so
+         * (which will have caused "DSN" to be given in the EHLO
+         * response). The code itself is included only if configured in
+         * at build time. */
+
+        case ENV_MAIL_OPT_RET:
+          /* Check if RET has already been set */
+          if (dsn_ret > 0) {
+            synprot_error(L_smtp_syntax_error, 501, NULL,
+              US"RET can be specified once only");
+            goto COMMAND_LOOP;
+          }
+          dsn_ret = (strcmpic(value, US"HDRS") == 0)? dsn_ret_hdrs :
+                  (strcmpic(value, US"FULL") == 0)? dsn_ret_full : 0;
+          DEBUG(D_receive) debug_printf("DSN_RET: %d\n", dsn_ret);
+          /* Check for invalid invalid value, and exit with error */
+          if (dsn_ret == 0) {
+            synprot_error(L_smtp_syntax_error, 501, NULL,
+              US"Value for RET is invalid");
+            goto COMMAND_LOOP;
+          }
+          break;
+        case ENV_MAIL_OPT_ENVID:
+          /* Check if the dsn envid has been already set */
+          if (dsn_envid != NULL) {
+            synprot_error(L_smtp_syntax_error, 501, NULL,
+              US"ENVID can be specified once only");
+            goto COMMAND_LOOP;
+          }
+          dsn_envid = string_copy(value);
+          DEBUG(D_receive) debug_printf("DSN_ENVID: %s\n", dsn_envid);
+          break;
+#endif
+
         /* Handle the AUTH extension. If the value given is not "<>" and either
         the ACL says "yes" or there is no ACL but the sending host is
         authenticated, we set it up as the authenticated sender. However, if the
@@ -3633,6 +3693,89 @@
       rcpt_fail_count++;
       break;
       }
+    
+    #ifdef SUPPORT_DSN
+    /* Set the DSN flags orcpt and dsn_flags from the session*/
+    orcpt = NULL;
+    flags = 0;
+    
+    if (esmtp) for(;;)
+      {
+      uschar *name, *value, *end;
+      int size;
+
+      if (!extract_option(&name, &value))
+      {
+         break;
+      }
+
+      if (strcmpic(name, US"ORCPT") == 0)
+      {
+        /* Check whether orcpt has been already set */
+        if (orcpt != NULL) {
+          synprot_error(L_smtp_syntax_error, 501, NULL,
+            US"ORCPT can be specified once only");
+          goto COMMAND_LOOP;
+        }
+        orcpt = string_copy(value);
+        DEBUG(D_receive) debug_printf("DSN orcpt: %s\n", orcpt);
+      }
+
+      else if (strcmpic(name, US"NOTIFY") == 0)
+      {
+        /* Check if the notify flags have been already set */
+        if (flags > 0)
+        {
+          synprot_error(L_smtp_syntax_error, 501, NULL,
+              US"NOTIFY can be specified once only");
+          goto COMMAND_LOOP;
+        }
+        if (strcmpic(value, US"NEVER") == 0) flags |= rf_notify_never; else
+          {
+          uschar *p = value;
+          while (*p != 0)
+            {
+            uschar *pp = p;
+            while (*pp != 0 && *pp != ',') pp++;
+              if (*pp == ',') *pp++ = 0;
+            if (strcmpic(p, US"SUCCESS") == 0) {
+                DEBUG(D_receive) debug_printf("GC: Setting notify success\n");
+                flags |= rf_notify_success;
+            }
+            else if (strcmpic(p, US"FAILURE") == 0) {
+                DEBUG(D_receive) debug_printf("GC: Setting notify failure\n");
+                flags |= rf_notify_failure;
+            }
+            else if (strcmpic(p, US"DELAY") == 0) {
+                DEBUG(D_receive) debug_printf("GC: Setting notify delay\n");
+                flags |= rf_notify_delay;
+            }
+            else
+            {
+              /* Catch any strange values */
+              synprot_error(L_smtp_syntax_error, 501, NULL,
+                US"Invalid value for NOTIFY parameter");
+              goto COMMAND_LOOP;
+            }
+            p = pp;
+            }
+            DEBUG(D_receive) debug_printf("DSN Flags: %x\n", flags);
+          }
+      }
+
+      /* Unknown option. Stick back the terminator characters and break
+      the loop. An error for a malformed address will occur. */
+
+      else
+        {
+        DEBUG(D_receive) debug_printf("Invalid dsn command: %s : %s\n", name, value);
+        name[-1] = ' ';
+        value[-1] = '=';
+        break;
+        }
+      }
+    #endif
+
 
     /* Apply SMTP rewriting then extract the working address. Don't allow "<>"
     as a recipient address */
@@ -3747,6 +3890,24 @@
       if (user_msg == NULL) smtp_printf("250 Accepted\r\n");
         else smtp_user_msg(US"250", user_msg);
       receive_add_recipient(recipient, -1);
+      
+      #ifdef SUPPORT_DSN
+      
+      /* Set the dsn flags in the recipients_list */
+      if (orcpt != NULL)
+         recipients_list[recipients_count-1].orcpt = orcpt;
+      else
+         recipients_list[recipients_count-1].orcpt = NULL;
+         
+      if (flags != 0)
+         recipients_list[recipients_count-1].dsn_flags = flags;
+      else
+         recipients_list[recipients_count-1].dsn_flags = 0;
+         debug_printf("DSN-AJ(smtp-in): orcpt: %s  flags: %d\n", recipients_list[recipients_count-1].orcpt, recipients_list[recipients_count-1].dsn_flags);
+
+
+      #endif
+      
       }
 
     /* The recipient was discarded */
diff -Naur exim-4.82_RC5.orig/src/spool_in.c exim-4.82_RC5/src/spool_in.c
--- exim-4.82_RC5.orig/src/spool_in.c	2013-10-27 21:46:25.000000000 +0100
+++ exim-4.82_RC5/src/spool_in.c	2013-10-27 21:47:32.000000000 +0100
@@ -293,6 +293,13 @@
 spam_score_int = NULL;
 #endif
 
+#ifdef SUPPORT_DSN
+#ifndef COMPILE_UTILITY
+dsn_ret = 0;
+dsn_envid = NULL;
+#endif  /* COMPILE_UTILITY */
+#endif
+
 /* Generate the full name and open the file. If message_subdir is already
 set, just look in the given directory. Otherwise, look in both the split
 and unsplit directories, as for the data file above. */
@@ -467,6 +474,19 @@
     case 'd':
     if (Ustrcmp(p, "eliver_firsttime") == 0)
       deliver_firsttime = TRUE;
+    #ifdef SUPPORT_DSN
+    #ifndef COMPILE_UTILITY
+    /* Check if the dsn flags have been set in the header file */
+    else if (Ustrncmp(p, "sn_ret", 6) == 0)
+    {
+      dsn_ret= atoi(big_buffer + 8);
+    }
+    else if (Ustrncmp(p, "sn_envid", 8) == 0)
+    {
+      dsn_envid = string_copy(big_buffer + 11);
+    }
+    #endif  /* COMPILE_UTILITY */
+    #endif
     break;
 
     case 'f':
@@ -554,7 +574,7 @@
       tls_in.sni = string_unprinting(string_copy(big_buffer + 9));
     break;
     #endif
-
+ 
     default:    /* Present because some compilers complain if all */
     break;      /* possibilities are not covered. */
     }
@@ -604,6 +624,10 @@
   {
   int nn;
   int pno = -1;
+  #ifdef SUPPORT_DSN
+  int dsn_flags = 0;
+  uschar *orcpt = NULL;
+  #endif
   uschar *errors_to = NULL;
   uschar *p;
 
@@ -672,10 +696,19 @@
     }
 
   /* Handle current format Exim 4 spool files */
+  /* Spool file is modified if DSN is supported
+     Original was "address errors_to len(errors_to),pno
+     New for DSN support is now:
+     "address errors_to orcpt len(errors_to),len(orcpt),pno,dsn_flags */
 
   else if (*p == '#')
     {
     int flags;
+
+    #ifndef COMPILE_UTILITY
+      DEBUG(D_deliver) debug_printf("**** SPOOL_IN - Exim 4 standard format spoolfile\n");
+    #endif  /* COMPILE_UTILITY */
+
     (void)sscanf(CS p+1, "%d", &flags);
 
     if ((flags & 0x01) != 0)      /* one_time data exists */
@@ -688,15 +721,82 @@
         {
         p -= len;
         errors_to = string_copy(p);
+        }	
+      }
+
+    *(--p) = 0;   /* Terminate address */
+    }
+    #ifdef SUPPORT_DSN
+    else if (*p == '!') /* Handle Exim4 + DSN spool files */
+    {
+    int flags;
+    int temp_dsn_flags;
+
+    #ifndef COMPILE_UTILITY
+      DEBUG(D_deliver) debug_printf("**** SPOOL_IN - C&W DSN format spoolfile\n");
+    #endif  /* COMPILE_UTILITY */
+    
+    sscanf(CS p+1, "%d,%d", &flags, &temp_dsn_flags);
+    
+    if (((flags & 0x01) != 0) || (temp_dsn_flags > 0)) /* one_time data or dsn_flags exist */  
+      {
+      int len;
+      int len_orcpt;
+
+      #ifndef COMPILE_UTILITY
+        DEBUG(D_deliver) debug_printf("**** spool_in dsn_flags = 0\n");
+      #endif  /* COMPILE_UTILITY */
+
+      dsn_flags = 0;
+      
+      while (isdigit(*(--p)) || *p == ',' || *p == '-');
+      sscanf(CS p+1, "%d,%d,%d,%d", &len, &len_orcpt, &pno, &dsn_flags);
+       
+      *p = 0;
+      if (len_orcpt > 0)
+        {
+          p -= len_orcpt;
+          orcpt = string_copy(p);
         }
+      *(--p) = 0; /* change the space to a NULL */
+
+      if (len > 0)
+        {
+        p -= len;
+        errors_to = string_copy(p);
+        }	
       }
 
     *(--p) = 0;   /* Terminate address */
     }
+    #endif
+    #ifndef COMPILE_UTILITY
+    else
+    {
+       DEBUG(D_deliver) debug_printf("**** SPOOL_IN - No additional fields\n");
+    }
+    #endif  /* COMPILE_UTILITY */
+  
+  #ifdef SUPPORT_DSN
+    #ifndef COMPILE_UTILITY
+      DEBUG(D_deliver) debug_printf("**** SPOOL_IN - address: |%s| errorsto: |%s| orcpt: |%s| dsn_flags: %d\n",
+      big_buffer, errors_to, orcpt, dsn_flags);
+    #endif  /* COMPILE_UTILITY */
+  #endif
+  #ifndef SUPPORT_DSN
+    #ifndef COMPILE_UTILITY
+      DEBUG(D_deliver) debug_printf("**** SPOOL_IN - address: |%s| errorsto: |%s|\n",
+      big_buffer, errors_to);
+    #endif  /* COMPILE_UTILITY */
+  #endif
 
   recipients_list[recipients_count].address = string_copy(big_buffer);
   recipients_list[recipients_count].pno = pno;
   recipients_list[recipients_count].errors_to = errors_to;
+  #ifdef SUPPORT_DSN
+  recipients_list[recipients_count].orcpt = orcpt;
+  recipients_list[recipients_count].dsn_flags = dsn_flags;
+  #endif
   }
 
 /* The remainder of the spool header file contains the headers for the message,
diff -Naur exim-4.82_RC5.orig/src/spool_out.c exim-4.82_RC5/src/spool_out.c
--- exim-4.82_RC5.orig/src/spool_out.c	2013-10-27 21:46:25.000000000 +0100
+++ exim-4.82_RC5/src/spool_out.c	2013-10-27 21:47:32.000000000 +0100
@@ -234,6 +234,15 @@
 if (tls_in.sni != NULL)		 fprintf(f, "-tls_sni %s\n",    string_printing(tls_in.sni));
 #endif
 
+#ifdef SUPPORT_DSN
+/* Write the dsn flags to the spool header file */
+DEBUG(D_deliver) debug_printf("DSN: Write SPOOL :-dsn_envid %s\n", dsn_envid);
+if (dsn_envid != NULL) fprintf(f, "-dsn_envid %s\n", dsn_envid);
+DEBUG(D_deliver) debug_printf("DSN: Write SPOOL :-dsn_ret %d\n", dsn_ret);
+if (dsn_ret != 0) fprintf(f, "-dsn_ret %d\n", dsn_ret);
+#endif
+
+
 /* To complete the envelope, write out the tree of non-recipients, followed by
 the list of recipients. These won't be disjoint the first time, when no
 checking has been done. If a recipient is a "one-time" alias, it is followed by
@@ -244,14 +253,36 @@
 for (i = 0; i < recipients_count; i++)
   {
   recipient_item *r = recipients_list + i;
-  if (r->pno < 0 && r->errors_to == NULL)
+#ifdef SUPPORT_DSN
+DEBUG(D_deliver) debug_printf("DSN: Flags :%d\n", r->dsn_flags);
+#endif
+  if (r->pno < 0 && r->errors_to == NULL
+    #ifdef SUPPORT_DSN
+     && r->dsn_flags == 0
+    #endif
+    )
     fprintf(f, "%s\n", r->address);
   else
     {
     uschar *errors_to = (r->errors_to == NULL)? US"" : r->errors_to;
+    #ifdef SUPPORT_DSN
+    uschar *orcpt = (r->orcpt == NULL)? US"" : r->orcpt;
+    fprintf(f, "%s %s %s %d,%d,%d,%d!1\n", r->address, errors_to, orcpt, 
+      Ustrlen(errors_to), Ustrlen(orcpt), r->pno, r->dsn_flags);
+    #else
     fprintf(f, "%s %s %d,%d#1\n", r->address, errors_to,
       Ustrlen(errors_to), r->pno);
+    #endif
     }
+    
+    #ifdef SUPPORT_DSN
+      DEBUG(D_deliver) debug_printf("DSN :**** SPOOL_OUT - address: |%s| errorsto: |%s| orcpt: |%s| dsn_flags: %d\n",
+         r->address, r->errors_to, r->orcpt, r->dsn_flags);
+    #endif
+    #ifndef SUPPORT_DSN
+      DEBUG(D_deliver) debug_printf("**** SPOOL_OUT - address: |%s| errorsto: |%s|\n",
+         r->address, r->errors_to);
+    #endif
   }
 
 /* Put a blank line before the headers */
diff -Naur exim-4.82_RC5.orig/src/structs.h exim-4.82_RC5/src/structs.h
--- exim-4.82_RC5.orig/src/structs.h	2013-10-27 21:46:25.000000000 +0100
+++ exim-4.82_RC5/src/structs.h	2013-10-27 21:47:32.000000000 +0100
@@ -282,7 +282,9 @@
   BOOL    verify_sender;          /* Use this router when verifying a sender */
   BOOL    uid_set;                /* Flag to indicate uid is set */
   BOOL    unseen;                 /* If TRUE carry on, even after success */
-
+#ifdef SUPPORT_DSN
+  BOOL    dsn_process;            /* If TRUE, activate DSN for this router */
+#endif
   int     self_code;              /* Encoded version of "self" */
   uid_t   uid;                    /* Fixed uid value */
   gid_t   gid;                    /* Fixed gid value */
@@ -547,6 +549,12 @@
   uschar *auth_id;		  /* auth "login" name used by transport */
   uschar *auth_sndr;		  /* AUTH arg to SMTP MAIL, used by transport */
 
+  #ifdef SUPPORT_DSN
+  uschar *dsn_orcpt;              /* DSN orcpt value */
+  int  dsn_flags;                 /* DSN flags */
+  uschar *dsn_aware;              /* DSN aware flag */
+  #endif
+
   uid_t   uid;                    /* uid for transporting */
   gid_t   gid;                    /* gid for transporting */
 
diff -Naur exim-4.82_RC5.orig/src/transport.c exim-4.82_RC5/src/transport.c
--- exim-4.82_RC5.orig/src/transport.c	2013-10-27 21:46:25.000000000 +0100
+++ exim-4.82_RC5/src/transport.c	2013-10-27 21:47:32.000000000 +0100
@@ -1802,6 +1802,11 @@
 
   argv = child_exec_exim(CEE_RETURN_ARGV, TRUE, &i, FALSE, 0);
 
+  #ifdef SUPPORT_DSN
+  /* Call with the dsn flag */
+  if (smtp_use_dsn) argv[i++] = US"-MCD";
+  #endif
+
   if (smtp_authenticated) argv[i++] = US"-MCA";
 
   #ifdef SUPPORT_TLS
diff -Naur exim-4.82_RC5.orig/src/transports/smtp.c exim-4.82_RC5/src/transports/smtp.c
--- exim-4.82_RC5.orig/src/transports/smtp.c	2013-10-27 21:46:25.000000000 +0100
+++ exim-4.82_RC5/src/transports/smtp.c	2013-10-27 21:47:32.000000000 +0100
@@ -242,6 +242,16 @@
 #endif
 };
 
+#ifdef SUPPORT_DSN
+/* some DSN flags for use later */
+
+static int   rf_list[] = {rf_notify_never, rf_notify_success,
+  rf_notify_failure, rf_notify_delay };
+
+static uschar *rf_names[] = { "NEVER", "SUCCESS", "FAILURE", "DELAY" };
+#endif
+
+
 
 /* Local statics */
 
@@ -1079,6 +1089,27 @@
   else if (new[0] != 0) local_authenticated_sender = new;
   }
 
+#ifdef SUPPORT_DSN
+/* Add any DSN flags to the mail command */
+
+if (smtp_use_dsn)
+  {
+  uschar *p = buffer;
+  if (dsn_ret == dsn_ret_hdrs)
+    {
+    strcpy(p, " RET=HDRS");
+    while (*p) p++;
+    }
+  else if (dsn_ret == dsn_ret_full)
+    {
+    strcpy(p, " RET=FULL");
+    while (*p) p++;
+    }
+  if (dsn_envid != NULL)
+    string_format(p, sizeof(buffer) - (p-buffer), " ENVID=%s", dsn_envid);
+  }
+#endif
+
 /* Add the authenticated sender address if present */
 
 if ((smtp_authenticated || ob->authenticated_sender_force) &&
@@ -1587,6 +1618,14 @@
     {DEBUG(D_transport) debug_printf("PRDR usable\n");}
 #endif
 
+  #ifdef SUPPORT_DSN
+  /* Note if the server supports DSN */
+  smtp_use_dsn = dsn &&
+    esmtp && pcre_exec(regex_DSN, NULL, CS buffer, (int)Ustrlen(CS buffer), 0,
+       PCRE_EOPT, NULL, 0) >= 0;
+  DEBUG(D_transport) debug_printf("use_dsn=%d\n", smtp_use_dsn);
+  #endif
+
   /* Note if the response to EHLO specifies support for the AUTH extension.
   If it has, check that this host is one we want to authenticate to, and do
   the business. The host name and address must be available when the
@@ -1746,18 +1785,66 @@
   int count;
   BOOL no_flush;
 
+  #ifdef SUPPORT_DSN
+  /* philb - set dsn_aware flag for this recipient */
+  if(smtp_use_dsn)
+     addr->dsn_aware = string_copy("Y");
+  else
+     addr->dsn_aware = string_copy("N");
+  #endif
+
   if (addr->transport_return != PENDING_DEFER) continue;
 
   address_count++;
   no_flush = smtp_use_pipelining && (!mua_wrapper || addr->next != NULL);
 
+   #ifdef SUPPORT_DSN
+   /* Add any DSN flags to the rcpt command and add to the sent string */
+
+   p = buffer;
+   *p = 0;
+
+   if (smtp_use_dsn)
+     {
+     if ((addr->dsn_flags & rf_dsnflags) != 0)
+       {
+       int i;
+       BOOL first = TRUE;
+       strcpy(p, " NOTIFY=");
+       while (*p) p++;
+       for (i = 0; i < 4; i++)
+         {
+         if ((addr->dsn_flags & rf_list[i]) != 0)
+           {
+           if (!first) *p++ = ',';
+           first = FALSE;
+           strcpy(p, rf_names[i]);
+           while (*p) p++;
+           }
+         }
+       }
+
+     if (addr->dsn_orcpt != NULL)
+       string_format(p, sizeof(buffer) - (p-buffer), " ORCPT=%s",
+         addr->dsn_orcpt);
+     }
+
+   #endif
+
+
   /* Now send the RCPT command, and process outstanding responses when
   necessary. After a timeout on RCPT, we just end the function, leaving the
   yield as OK, because this error can often mean that there is a problem with
   just one address, so we don't want to delay the host. */
 
+ #ifdef SUPPORT_DSN
+  count = smtp_write_command(&outblock, no_flush, "RCPT TO:<%s>%s%s\r\n",
+    transport_rcpt_address(addr, tblock->rcpt_include_affixes), igquotstr, buffer);
+ #else
   count = smtp_write_command(&outblock, no_flush, "RCPT TO:<%s>%s\r\n",
     transport_rcpt_address(addr, tblock->rcpt_include_affixes), igquotstr);
+ #endif
+
   if (count < 0) goto SEND_FAILED;
   if (count > 0)
     {