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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 Mailbox is used with your account.

What is a Mailbox?

Section titled “What is a Mailbox?”

A Mailbox 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 Mailboxes when they reconnect.

The Mailbox cannot read messages and does not act as a traditional server.

Why use a Mailbox?

Section titled “Why use a Mailbox?”

Mailbox 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 Mailbox works (high level)

Section titled “How Mailbox works (high level)”
  1. You install the Anonomi Postbox app on a separate device
  2. You link it to your Anonomi account by scanning a QR code
  3. The Mailbox stays online and receives encrypted messages on your behalf
  4. When your main device comes online, it fetches messages automatically

All communication remains end-to-end encrypted.

Mailbox in Settings

Section titled “Mailbox in Settings”

From Settings → Anonomi Postbox, you can:

  • Set up a new Mailbox
  • Link or unlink a Mailbox device
  • View Mailbox status
  • Disable Mailbox usage entirely

Mailbox behavior depends on your Connections settings — internet access uses Tor when enabled.

Security considerations

Section titled “Security considerations”

Using a Mailbox changes your threat model slightly:

  • The Mailbox device is a separate point of exposure
  • If seized, it may reveal:
    • That you use Anonomi
    • That a Mailbox 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 Mailbox device

If Mailbox increases risk in your environment, do not use it — Anonomi works without it.

When not to use Mailbox

Section titled “When not to use Mailbox”

Avoid using Mailbox if:

  • You expect device seizures
  • You cannot physically secure the Mailbox device
  • Being continuously reachable increases risk
  • Offline-only workflows are safer for you

Mailbox is optional by design.

Section titled “Related documentation”