A current project has a single exchange server (2013) configured for both the testing and production environments. I'm looking for possible solutions that will either allow me to disable or re-route email notifications.
I have tried the following without any success
<smtp deliveryMethod="SpecifiedPickupDirectory" from="email@example.com">
If you are talking about the email-event in one of the default client activity that trigger email everytime it receives tasklist, then just create a dummy dafault activity and move that email-event into the dummy activity while testing. Since dummy activity never receive any tasklist, email-event never trigger. After the testing is done, then restore that email-event into the same dafault activity and delete the dummy activity is the simplest thing to do.
If you are talking about the tasklist notification in the dafault client event, then you can always disable that in the set-up wizard.