When trying to assign a user to workflow, ISA should provide either a warning or hard stop if the user does not have an email assigned in their profile.
Conversely, if it does not provide a warning when assigning the workflow, a report that displays which users have workflows but no email addresses would be helpful.
Another alternative is that when creating a new user, a warning could appear if the email address is blank, then it would not be an issue for the workflow, but still a report could be available of users who have workflow but no email address.
What happens when workflow is generated for a user that has no email address? Does it simply skip them and provide no feedback?