It does. The relevant RFC says they don't have to matter and that senders shouldn't assume they do or don't. That means that both Google and Netflix are followi

It does. The relevant RFC says they don't have to matter and that senders shouldn't assume they do or don't. That means that both Google and Netflix are following the standard. The problem isn't with either company's compliance with the RFC, but that's not saying a lot. A mail provider could legally ignore all vowels in mailbox names. (Similarly, although the RFC does say hosts shouldn't have case-sensitive local-parts, it doesn't say that senders can assume that local-parts are case-insensitive.)