diff -urN ../exim-4.90.1.orig/src/spool_mbox.c ./src/spool_mbox.c
--- ../exim-4.90.1.orig/src/spool_mbox.c	2018-02-08 15:22:40.000000000 +0200
+++ ./src/spool_mbox.c	2018-02-26 14:34:55.656938000 +0200
@@ -77,8 +77,9 @@
 
   temp_string = expand_string(
     US"From ${if def:return_path{$return_path}{MAILER-DAEMON}} ${tod_bsdinbox}\n"
-    "${if def:sender_address{X-Envelope-From: <${sender_address}>\n}}"
-    "${if def:recipients{X-Envelope-To: ${recipients}\n}}");
+    "X-Envelope-From: <${sender_address}>\n"
+    "${if def:received_for{X-Envelope-To: <${received_for}>\n}"
+    "{${if def:recipients{${if match{${recipients}}{\\N.*[, ]\\N}{}{X-Envelope-To: <${recipients}>\n}}}}}}");
 
   if (temp_string)
     if (fwrite(temp_string, Ustrlen(temp_string), 1, mbox_file) != 1)