You have a single receive email, but it’s associated with a full HD wallet, so every receive will generate a brand new unused address for the sender. As the email is static, you could for example post it for donations and not have to worry about people being able to track anything you’ve received. Of course this only works with other Proton users which is kind of pointless, but perhaps it’s the start of some sort of interoperability standard?
They have support which you can contact, which while almost certainly isn’t important for you, for your aunty it might be useful.