I actually tried using both the Server Default and Customize options. No task notification emails were generated with either option. You were able to at least get emails to be generated? I am wondering if something is not set up correctly in adminUI - Services - Process Management - Server Settings - Email Settings or Task Notification Settings. Do you know of anything that needs to be set up here?
Also, what was the separate activity you used to send the notification? Did you do that in the same process? I am just starting out in Workbench/Workspace. I appreciate any assistance.