The logging program is meant to help you as the developer in a few ways. 
 A common way for programs to record events, actions or values that should or could be reviewed in the future
 Can be error situations that need to be addressed, internal values or even browser requests
 Level of detail can be changed at runtime in response to a situation you are investigating
 Debug logging requires a bit of guessing and experience to know what to log before you need it
 A standard table (LOG) that can be queried
 Minimal runtime impact
To enable the email function, you need to modify the internal procedure sendNotificationEmails and look for the comment:  “in here you will implement your email program”
Read the Logging developer documentation for input parameters definition. 

you will need to ftp the savf file to your Ibm I using the FTP instructions. 

Documentation is in the logging developer documentation.