How to send an email Log messages every end of the process?
It depends on your requirement, at end of every process you can pick the file from log directory based on date modified.
You can even append log details to a custom file & append details, finally mail.
If you are using the Queue in your Workflow, Get status of each item by using (Get Queue item and passing reference number).
Build a Table format in HTML inside Body of your Email and give brief status of each transaction item in Table format whether it’s success or Failure.You can Even classify the exception type if required and specify the reasons for failure (exception.message) as well.