If you have an end user who has turned on the option in the Workspace to receive emails, then the downside is that they will automatically receive an email for the work item instances that reach their Oracle BPM WorkSpace inbox. This is not a good option for someone who receives many instances every day.
If you want to customize the standard email Oracle BPM automatically sends end users if they have turned on this option, look at the activityNotification.mail file located inside your <OracleBPMEnterpriseInstallationDirectory>\conf directory.
This is just a sample XML file that you can edit. Once you edit the file, be sure to move this file into the Oracle BPM Enterprise Engine's home directory. You can determine the home directory to copy this file into by logging into the Process Administrator -> click "Engines" -> click the name of your Engine -> note the directory for the "Home Directory" (mine is C:\OraBPMSAEnterpriseHome\engines). Copy your modified activityNotification.mail file into this directory. Stop and restart the engine and test.
You also can also store the file in another directory if you specify the directory in the system property "fuego.server.notification.template.dir"
(e.g. java .... -Dfuego.server.notification.template.dir=/home/somedirectory/mytemplatefolder).