Email-Encryption

Bulk encrypt your .eml email files on Windows using GPG (Gpg4win) and Python.

📂 Repository Structure

Email-Encryption/         # Project root (Git repo)
├── .env                  # Your PGP key configuration
├── LICENSE               # Project license
├── README.md             # This guide
├── emails/               # Input folder for plaintext .eml files
│   └── README.md         # Notes on email placement
├── encrypted/            # Output folder for encrypted .eml files
│   └── README.md         # Notes on encrypted files
├── scripts/
│   └── encrypt_eml.py    # Main Python encryption script
└── .git/                 # Git metadata (ignore)

1. Prerequisites

• Windows 10/11
• Python 3.x (https://www.python.org/downloads/) with Add to PATH enabled.
• Gpg4win (https://gpg4win.org) for GPG tools and key management.

2. Install and Configure Gpg4win

1. Download and install Gpg4win, accepting default components (GnuPG, Kleopatra).

2. Open System Properties → Environment Variables.

3. Under System variables, edit Path and add two entries:

   • C:\Program Files (x86)\Gpg4win\bin
   • C:\Program Files (x86)\GnuPG\bin

4. Click OK to apply.

5. Verify in PowerShell/CMD:

   gpg --version

6. Run kleopatra.exe and import or create your PGP keys.

3. Python Dependencies

All required Python packages are pinned in requirements.txt for easy setup and reproducibility. From the project root, run:

pip install -r requirements.txt

4. Configure Your .env

At the project root, edit .env to include your PGP key ID or email:

# Set this to your own GPG key (email or key ID)
SELF_KEY=your@emailaddress.here

5. Prepare Your Emails

• Place all plaintext .eml files into the emails/ directory.
• The script will process every *.eml found there.

6. Run the Encryption Script

1. Open PowerShell/CMD and navigate to the scripts folder:

   cd path\to\Email-Encryption\scripts

2. Execute:

   python encrypt_eml.py

3. Encrypted files will be created in ../encrypted/ with the same filenames.

7. Verify Decryption in Thunderbird

1. Open Thunderbird, go to Local Folders.
2. Drag and drop the encrypted .eml files from encrypted/.
3. Thunderbird’s OpenPGP built-in support will prompt for your passphrase and render the decrypted content.

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© 2025 Lupton Consulting Inc., LLP. Licensed under the terms in LICENSE. Feel free to customize and extend.