Have a requirement to send email notification to multiple emails from workflow. As per the given requirements have derived the emails and concatenated with comma (,) and passed to the API createadhocrole to create.
You need to provide the correct email address but not the dummy address like 'email@example.com,firstname.lastname@example.org'. One more thing you can give only email address per one user or role. You cannot assign multiple addresses, if you do also it treats the entire string as one email address only.
After changing the email address, modify the notification preference to MAIL* and then send a notification.