I am facing problem for some user email field returning NULL even if the user has granted the email access to the app. When we check the scope parameter and the validity of the user Token thanks to the Debugger tool, everything is ok. The permission email has been accepted. But when we ask the Graph API for the email of the user with the valid user token, it does not appear at all.
Is there a way a user could prevent an app from getting his email even if he granted the email permission?