It's all a question of how low you want to set the bar. For external applications or internal applications with a huge user base, then you probably want to set the bar as low as possible.
But for an internal application with only a few tens of users, expecting someone to remember to put in their e-mail instead of their regular login when the application says "e-mail" is very reasonable.
I would expect my parents to figure that out, after being told no more than once - and I would surely do my best to get any IT project manager fired who couldn't figure it out after the third time.