+# ----- Routers -----
+
+begin routers
+
+delay:
+ driver = redirect
+ local_parts = ^delay
+ allow_defer
+ data = :defer: deliberate for test purposes
+
+bounces:
+ driver = accept
+ condition = ${if !def:sender_address}
+ transport = savebounce
+
+begin transports
+
+savebounce:
+ driver = appendfile
+ file = DIR/test-mail/bounce_message
+ user = CALLER
+
+# ----- Retry -----
+
+begin retry
+
+* * F,5d,100s