Barr Cyber LLC — Standalone Tool v4.2 — June 2026

Barr-Cyber Mailbox Viewer

Name: Barr-Cyber Mailbox Viewer
Availability: InStock
Author: Warren Barr

Offline MBOX Viewer — Also Included in Forensic G-Suite

MBOX Offline Google Takeout AES-256 Read-Only No Server Windows

Overview

Convert a Google Takeout .mbox export into a standalone, offline, read-only HTML viewer. Double-click index.html to open it. No server. No network connection. No installation beyond running the builder once.

Built for professionals who need to review archived Google Workspace email without a live account, without uploading data to a third-party service, and without keeping a server running. The viewer lives entirely on disk. When you're done, delete the folder.

Features

Memory-Safe Lazy Loading

Only the current message is held in memory. Large mailboxes don't require large RAM. Index loaded once — messages loaded on demand.

AES-256 Encrypted Delivery

Package the finished viewer as an AES-256 encrypted zip for secure delivery to a client or colleague. Password delivered separately.

Attachment Extraction

Attachments extracted and stored alongside messages. Image attachments preview inline on click. No external dependencies.

Thread Grouping

Messages grouped by thread. Navigate a conversation as a unit rather than as individual messages.

No Server Required

Works entirely under file://. Browser security limitations handled via script injection — no server, no command, no network.

Read-Only by Design

No send, reply, or forward capability. This is a viewer, not a client. Data stays on disk, untouched.

Multiprocessing Build Engine

Large mailboxes processed in parallel. Worker count auto-configured based on available cores. Diagnostics tab with real-time build log.

Least-Privilege Architecture

Runs without admin elevation. Only writes to user-chosen output folders. Designed for forensic environments where elevated processes are a liability.

System Requirements

Operating System	Windows 10 or Windows 11 (x64)
Runtime	Python 3.9+ (or use the packaged .exe — no Python required)
Dependencies	pyzipper (optional — required for AES-256 encrypted packaging only)
Browser	Firefox recommended for viewing large mailboxes under file://
Disk Space	Varies with mailbox size — viewer output is typically 1.2× the source .mbox

License

Per-client license. Each installer is issued to a specific licensee and is not transferable. The license permits use on machines controlled by the licensee only. Redistribution, resale, or sublicensing is prohibited. © Barr Cyber LLC — all rights reserved.

Licensed Clients

Download — v4.2

Enter your license key to verify your license and access the installer. Your key was provided at the time of licensing. If you don't have a key, contact Barr Cyber to get one issued.

License key format: BC-XXXX-XXXX-XXXX · Don't have a key? Contact warren@barr-cyber.com

SHA-256 — Verify before running

Download Installer →

Verifying Your Download

Always verify the SHA-256 hash of the installer before running it. The hash is displayed after your license is verified above. To check on Windows:

Open PowerShell and run:

Get-FileHash .\BarrCyberMailboxViewer.exe -Algorithm SHA256

The Hash value must match exactly what is shown above. If it doesn't match, do not run the installer — contact warren@barr-cyber.com.

Version History

Version	Released	Notes
v4.2	June 2026	Current release. Maintenance and packaging refinements; offline viewer core unchanged from v4.1.
v4.1	June 2026	Adds SENT / Received / All message filtering and a Conversations thread-collapse view. Refines From/To/Cc filter scoping. Adds the Barr-Cyber window icon to the app title bar. Installer now removes any prior version before installing. Offline viewer core unchanged.
v4.0	May 2026	Adds licensed update awareness. Each installer bound to a specific licensee via embedded key. Help menu with Check for Updates, About, and View License. No automatic downloads — updates notify and direct user to product page.
v3.0	May 2026	Initial release. MBOX to offline HTML viewer. Memory-safe lazy loading, AES-256 encrypted zip packaging, attachment extraction, thread grouping, multiprocessing build engine.

Also Included In

The Mailbox Viewer is bundled as a component of Forensic G-Suite — the full Google Workspace forensic investigation platform. If you need the full investigative toolkit including Admin CSV forensic parsing, chained audit ledger, and courtroom packet export, contact Barr Cyber to discuss a Forensic G-Suite license.

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