+
+And here's another submitted idea: "My actual suggestion is that if this model
+is followed, the parent process doesn't have to stop the callout process if it
+is taking too long to respond: it can return 450 to the incoming connection
+within the 5 minute SMTP command timeout and leave the callout process to
+continue, in the hope that it will eventually get a result and store it in the
+callout cache in time for the sender's next attempt."