Self-Hosted M365 Backup

A self-hosted, open-source tool to back up Microsoft 365 mailboxes to standard .eml files. It features a web UI for managing backups, background tasks, search, preview functionality, and secure Microsoft OAuth 2.0 login.

Features

• Web-Based Management Panel: Modern web interface for all operations.
• Secure Authentication: Microsoft Identity Platform OAuth 2.0 login with MFA support.
• Selective Backup: Choose specific users from the tenant list.
• Date Filtering: Back up items by date range.
• Background Tasks: Large jobs run asynchronously via Celery + Redis.
• Task Status Dashboard: Monitor task progress and results.
• Interactive Restore Portal:
  • Navigation through mailbox folders
  • List of emails in selected folder
  • In-browser email preview without downloading
• Privacy-by-Design: Email previews blurred by default, hover-to-reveal for admins.
• Full-Text Search: Search subject and body of emails.
• Automated Installation: Single install.sh script deploys the app on Ubuntu.

Architecture

• Backend: Python, Flask
• Web Server: Gunicorn + Nginx (Reverse Proxy)
• Background Tasks: Celery
• Queue/Broker: Redis
• Frontend: HTML, Pico.css, HTMX
• Authentication: Microsoft Identity Platform (OAuth 2.0)

Installation Guide

I. Azure Portal Configuration

1. App Registration:
   • Go to portal.azure.com → Azure Active Directory → App registrations → + New registration
   • Name the app (e.g., M365-Backup-Tool) and click Register
2. API Permissions:
   • Microsoft Graph → Add Permissions
   • Application Permissions: User.Read.All, Mail.Read.All
   • Delegated Permissions: User.Read
   • Click "Grant admin consent"
3. Redirect URI:
   • Authentication → + Add platform → Web
   • Enter: https://<your_server_ip>/get_token
4. Client Secret:
   • Certificates & secrets → + New client secret
   • Copy the secret value immediately

Required info: Tenant ID, Client ID, Client Secret Value

II. Server Installation

1. Requirements: Fresh Ubuntu 22.04 LTS server
2. Copy install.sh to the server
3. Make it executable:

   chmod +x install.sh

4. Run the script:

   sudo ./install.sh

5. Provide Azure credentials and list of admin emails
6. Wait for installation to complete; script outputs server access IP

Usage

• Open browser: https://<your_server_ip>
• Accept security warning (self-signed cert)
• Login with authorized Microsoft account
• New Backup: Start a new backup task
• Existing Backups: Browse, search, preview backups
• Tasks: Monitor background tasks and status

License

Open-source, MIT License.