Apple also hasn't fixed the Mail.app bug for years (sometimes, when you are in full screen mode, Mail.app suddenly activates and fills half the screen). Search

Apple also hasn't fixed the Mail.app bug for years (sometimes, when you are in full screen mode, Mail.app suddenly activates and fills half the screen). Search for it. There are countless threads about the issue online, and last time I checked noone knew of a way to prevent it. Imagine holding a presentation, or watching a film with someone, and suddenly your private emails fill half the screen...