What happens when you lose your phone

What happens when you leave your phone in the back of a taxi? It's gone, and so is everything signed in on it. With most email that's an annoying afternoon: you borrow a laptop, log in with your username and password, and you're back in your inbox before dinner.

On DMCN your password won't do that on its own. I want to be upfront about that, because it's the first thing anyone who knows email asks, and it's the thing that sank PGP for most people. Your password only unlocks your keys on a device you've already set up. The keys only live on your devices, and if you lose all of them, nobody can get your mail back, including us.

So why build it that way? With most providers, your password lets you in from any device, and when you've forgotten it, so does passing whatever checks they run instead. Those checks are a phone number, an old email address, or a support agent having a good day. That's a door, and it opens for anyone who can convince it, not only for you. If your provider can let you back in, it can let someone else in.

I think an account only your own devices can open is safer than one a password opens from anywhere, and that the price is a couple of minutes of setup most people will never need. But that's only true if losing a phone doesn't mean losing everything.

What happens if you still have another device?

This is the easy case, and it's the one I'd want everyone to be in.

1. On your laptop, or whatever you still have, open Settings, go to Privacy & security, and find the lost phone under "Your devices".
2. Remove it. It can no longer open your mailbox or send anything as you, on any of our servers.
3. Get a new phone, open the app, and ask to add it. It shows a code, you type the last four digits into your laptop, and you approve it there.

The lost phone still has whatever it had already downloaded, and its copy of your keys, locked behind your passkey or passphrase. If you think someone could get past that, you can also change your account key in Settings, so anything new is sealed to a key that phone has never seen.

What if it was your only device?

This is where a backup file comes in. You can export one from Settings at any time. It's your keys, encrypted with a passphrase or a passkey, and it's yours to keep. We never see it.

On a new device you import the backup, and the app has your keys again. It can't open your mailbox yet though, because the mailbox only opens on devices you've approved, and there's nobody left to approve it. So it offers to ask on its own:

1. You tap "I don't have another device" and ask to join.
2. The new device waits a week before it can open your mail.
3. If any device of yours is still around, it gets a notice at the top of the inbox and can cancel the request.

That wait is there on purpose. If someone stole your backup and your passphrase, they'd have to wait too, out in the open, and you could stop them from any device you still have. If you really have lost everything, a week is annoying, but you get your mail back.

One thing to check: a backup locked with a passkey only opens where that passkey is available. If your passkeys sync to your other devices or a password manager, you're fine. If the passkey only lived on the phone you lost, it can't open the backup, so a passphrase is the safer choice here.

What if you have neither?

Then the mail is gone, and I'm not going to soften that. Everything in your mailbox, your sent mail, your contacts and your settings are sealed to keys that only existed on your devices.

The address goes with it. We can't move it to a new key for you, because we have no safe way to tell you apart from someone claiming to be you, and a recovery anyone could talk us into would be a way in for them.

What should you do today?

It doesn't take long, and it covers almost every case above.

1. Add a second device. Your laptop and your phone are enough, and either one can let a replacement in.
2. Export a backup and keep it somewhere that isn't your laptop. A password manager or a USB stick in a drawer both work.
3. Leave "Lock when I leave" on in Settings. The app then locks a couple of minutes after you switch away from it, and closing it locks it straight away.

If you ever change your account key, make a new backup afterwards, because the old one won't match anymore.

Do those, and losing your phone is just losing your phone.