How would you "end to end encrypt" an email going from Super Secure Provider A to Outlook or Gmail? The encryption stops the millisecond it leaves Provider A's servers.
Correction: you can send links to a website where the recipient can see the text you wrote using a password.
Nothing about that is "email" anymore. The same method can be used to make "password protected SMS" for example. Just send a link to a website and a password. Encryption!
What we need is actual public key encryption/signing support on mail services, but that's not going to happen ever.
Plus as an Australian company the government can backdoor it without anyone legally being able to speak about it.