+
+B. Patch to remedy the problem
+==============================
+
+Index: sink.c
+===================================================================
+- --- sink.c (revision 5118)
++++ sink.c (revision 5119)
+@@ -262,7 +262,7 @@
+ const char *md1 = "MAILER-DAEMON", *md2 = "MAILER-DAEMON@";
+
+ /* don't bounce in reply to undeliverable bounces */
+- - if (!msg->return_path[0] ||
++ if (!msg || !msg->return_path[0] ||
+ strcmp(msg->return_path, "<>") == 0 ||
+ strcasecmp(msg->return_path, md1) == 0 ||
+ strncasecmp(msg->return_path, md2, strlen(md2)) == 0)
+