--- deliver.c.orig	2016-03-02 16:45:37.000000000 -0600
+++ deliver.c	2016-03-02 16:46:00.000000000 -0600
@@ -9,6 +9,7 @@
 
 
 #include "exim.h"
+#include <assert.h>
 
 
 /* Data block for keeping track of subprocesses for parallel remote
@@ -7904,17 +7905,30 @@
 uschar *
 deliver_get_sender_address (uschar * id)
 {
+int rc;
+uschar * new_sender_address,
+	* save_sender_address;
+
 if (!spool_open_datafile(id))
   return NULL;
 
 sprintf(CS spoolname, "%s-H", id);
-if (spool_read_header(spoolname, TRUE, TRUE) != spool_read_OK)
+save_sender_address = sender_address;
+
+rc = spool_read_header(spoolname, TRUE, TRUE);
+
+new_sender_address = sender_address;
+sender_address = save_sender_address;
+
+if (rc != spool_read_OK)
   return NULL;
 
+assert(new_sender_address);
+
 (void)close(deliver_datafile);
 deliver_datafile = -1;
 
-return sender_address;
+return new_sender_address;
 }
 
 /* vi: aw ai sw=2