Anonomi Postbox
Anonomi Postbox is a companion app that allows you to receive and send messages even when your main Anonomi device is offline.
From the Settings screen, you can configure and manage how Postbox is used with your account.
What is a Postbox?
Section titled “What is a Postbox?”A Postbox is a separate Anonomi Postbox app installed on another Android device.
Its role is simple:
- Receive encrypted messages from your contacts while you are offline
- Store those messages securely
- Deliver them automatically when your main device comes online again
Likewise, messages you send while your contacts are offline can be delivered through their Postboxes when they reconnect.
The Postbox cannot read messages and does not act as a traditional server.
Why use a Postbox?
Section titled “Why use a Postbox?”Postbox is useful when:
- Your phone is often offline
- You intentionally keep your main device disconnected
- You want asynchronous communication without constant connectivity
Typical setups include:
- A spare Android phone
- A device left at home
- A device kept powered and connected to Wi-Fi
How Postbox works (high level)
Section titled “How Postbox works (high level)”- You install the Anonomi Postbox app on a separate device
- You link it to your Anonomi account by scanning a QR code
- The Postbox stays online and receives encrypted messages on your behalf
- When your main device comes online, it fetches messages automatically
All communication remains end-to-end encrypted.
Postbox in Settings
Section titled “Postbox in Settings”From Settings → Anonomi Postbox, you can:
- Set up a new Postbox
- Link or unlink a Postbox device
- View Postbox status
- Disable Postbox usage entirely
Postbox behavior depends on your Connections settings — internet access uses Tor when enabled.
Security considerations
Section titled “Security considerations”Using a Postbox changes your threat model slightly:
- The Postbox device is a separate point of exposure
- If seized, it may reveal:
- That you use Anonomi
- That a Postbox is linked to your account
- It does not reveal message contents
Best practices:
- Use a dedicated device
- Keep it physically secure
- Keep it updated
- Do not log into your main Anonomi app on the Postbox device
If Postbox increases risk in your environment, do not use it — Anonomi works without it.
When not to use Postbox
Section titled “When not to use Postbox”Avoid using Postbox if:
- You expect device seizures
- You cannot physically secure the Postbox device
- Being continuously reachable increases risk
- Offline-only workflows are safer for you
Postbox is optional by design.