--- a/maildrop.c	Thu May 29 16:02:35 2014 +0500
+++ b/maildrop.c	Wed Aug 20 21:46:02 2014 +0500
@@ -112,7 +112,7 @@
 	if (event_dispatch() < 0)
 		fatal("event_dispatch");
 
-	logit(LOG_INFO, "maildrop process exiting");
+	logit(LOG_INFO, "%zu: maildrop process exiting", session_id);
 	_exit(0);
 }