I'm a longtime fastmail customer, and I like the service, but they still have no answer for Australia's Access and Assistance Bill, aside from all the other privacy disadvantages they have against Protonmail.
The Access and Assistance Bill doesn't meaningfully impact Fastmail: They do not need to implement a backdoor because they do not provide an end-to-end encrypted service.
They obviously chose not to offer end-to-end before, but now they can't even if they wanted to. So it's a distinction without a difference. It's open by default.
The Access and Assistance Bill doesn't prevent anybody from offering end to end encryption.
The media coverage was very "sky is falling" but the reality is that it only requires you decrypt content to which you already hold the keys or to which you can obtain the keys without compromising the security of untargeted users.
This isn't something they would or could implement after the fact regardless of the law in
question. It'd be impossible to provide Fastmail's product as end-to-end. And that's okay!
Please drop the FUD. It's not helping the discussion.