Q-Day Email q-day email
EN ES Login

How to Use the @@ Protocol — Step by Step

Learn how to register, send, receive, and read emails with the @@ split-body protocol.

1 Register in the System

To use the @@ protocol, you first need an account and your RSA-4096 key pair.

Create your account

  1. Go to the registration page.
  2. Fill in the form with your email address, name, surname, and a secure password.
  3. Check your inbox — you will receive a verification email.
  4. Click the verification link in the email to activate your account.

Generate your RSA keys

  1. Log in and go to your Panel (⚙️ icon in the top bar).
  2. In the "Your Keys" section, click "Generate New Keys" — a 4096-bit RSA key pair will be created.
  3. Download your private key (.pem file). Keep it safe! It is the only way to decrypt your messages.
  4. Save the private key in a secure location — a password manager or an encrypted USB drive.
  5. Your public key is automatically stored on the server and linked to your @@ address.
✅ Done!
You now have an active @@ account with your RSA keys. You can receive encrypted emails at yourname@@domain.com.

2 Send an @@ Email

When you send an email with the @@ protocol, the body (eBody) is split from the message and stored on the server. Only the header (eHead) travels by email.

Compose the message

  1. Go to the Send page from the navigation menu.
  2. Enter the recipient's email address using the @@ format: recipient@@domain.com.
  3. Click on the subject field — the system will automatically look up the recipient's public key.
  4. If the recipient is registered, their public key will be loaded automatically.

Send the message

  1. Write your message in the body field — it will be encrypted with AES-256-CBC.
  2. (Optional and Recommended) Set a PIN that the recipient must enter to download the eBody.
  3. (Optional and Recommended) Require second-channel authorization (PWA) for quantum-resistant protection.
  4. Press Send. The system splits the message, encrypts the body, stores the eBody on the server, and sends only the eHead via email.
💡 Pro Tip
The recipient does NOT need to be registered before you send the email. If they are not registered yet, the system will hold the eBody until they register and generate their keys.

3 Receive an @@ Email

When someone sends you an @@ email, you receive the eHead in your inbox. You need to download the eBody separately.

Get the eHead and token

  1. Check your regular email inbox — you will see a message from the sender with the subject line.
  2. Look for the DAE email: it contains the eHead (a .dae attachment) and a download token.
  3. Download and save the .dae attachment (the eHead file) to your device.
  4. Copy the download token from the email body — you will need it to download the eBody.

⚠️ Second-Channel Authorization (MANDATORY if enabled by sender)

  1. If the sender enabled second-channel protection, you cannot download the eBody without first authorizing it from a mobile phone. You will receive a push notification in your PWA app.
  2. Open the PWA app from a mobile phone (Android or iPhone). The PWA is not available from desktop computers.
  3. Find the pending eBody and press "Authorize Download" — this unlocks the download for 5 minutes. Without this authorization, the download link will not work.
📱 The PWA app is only accessible from a mobile phone. If the sender enabled this protection, you must authorize the download from the PWA before you can download the eBody. Without this step, not even the private key can grant access to the content.

Download the eBody

  1. If the token is encrypted, go to the Decrypt Token page and use your private key to decrypt it.
  2. Copy the decrypted download token.
  3. Go to the Download page.
  4. Paste the download token into the form.
  5. If the sender set a PIN, enter it here.
  6. Press Download — the eBody file will be saved to your device.

4 Read / Decrypt the Message

Now you have both parts: the eHead (.dae file) and the eBody file. You need to combine them to read the message.

Method A: Decrypt Page (standalone)

  1. Go to the Decrypt page.
  2. Upload the eHead file (.dae).
  3. Upload the eBody file.
  4. Paste your private key in PEM format.
  5. Press Decrypt — the system reconstructs the original message.
  6. Optionally download the complete reconstructed .eml file.

Method B: Inbox Viewer (online)

  1. Go to your Inbox from the navigation menu.
  2. Click "View" on the email you want to read.
  3. Enter your private key in the form.
  4. The decrypted message is displayed on screen.
✅ Done!
You have successfully received and read an @@ email. The eBody never traveled with the message — privacy by architecture, not by encryption.

Quick Reference

Action Where Address Type
Register ?page=register @
Generate Keys panel.php —
Send Email ?page=send @@
Download eBody ?page=download Token
Decrypt ?page=decrypt —
Inbox ?page=inbox —
PWA Authorization ?page=pwa —
Decrypt Token ?page=decrypt-token —

🔬 How the @@ Protocol Works

A normal email uses a single @ symbol. The @@ protocol adds a second @ to indicate that the body (eBody) is split from the message. The eHead travels by email, the eBody stays on the server, and they are only reunited when the recipient decrypts the message.

user@domain.com → user@@domain.com