[e12e]

Carussell: have you ever worked in first-line support?

To paraphrase a friend: "If I never hear the phrase: Why isn't my email working? I have an iphone...", I'll die happy."

I can appreciate that it's nice to be able to use space as a character, any reason you can't just substitute "." or "," on mobile (in terms of UX, obviously)?

Btw, I have no affiliation with fastmail.

> and guarnteed non-password-reuse of device passwords.

This should be easy to guarantee at creation-time:

  For user A, all devices a...x
  When generating a new device password p
  Check p against all historical device passwords
    for devices a..x
  If no match, use p
  Else generate p' and try again

When a valid (non-reuse) password has been found, it can be stored in non-reversible form (salt+hash, optional stretching).

I would too like to know what fastmail actually do, though.