Mailbox Viewer

Mailbox Viewer is an open-source tool that converts mbox and PST files into a static, Gmail-style website with in-browser semantic and full-text search.

Mailbox Viewer turns mailbox export files into a static website featuring a Gmail-like interface with conversations, labels, and keyboard shortcuts. It parses .pst, .ost, mbox, Maildir, and .eml archives, deduplicates messages, and extracts text from attachments such as PDF, Word, Excel, and PowerPoint files. The build step outputs Parquet tables and word indexes, allowing DuckDB-WASM to query data directly in the browser over byte ranges. Smart search utilizes a transformers.js embedding model executed locally in the browser to match messages by meaning. Designed for public-records and FOIA responses, the resulting files can be hosted on static platforms like Cloudflare R2, Vercel, Netlify, or GitHub Pages.

Mailbox Viewer at a glance

Best for: Researcher
Runs on: Web, CLI, self-hosted, open source
Pricing: Free
Released: October 2026
Category: AI search engine
Website: github.com/rahimnathwani/mailbox-viewer

Key features

Supports .pst, .ost, mbox, Maildir, and .eml mailbox imports
Gmail-style interface with conversations, labels, stars, and dark mode
Standard Gmail search operators including from:, to:, subject:, and exclusions
Text extraction and search inside PDF, Word, Excel, PowerPoint, and RTF attachments
In-browser semantic search powered by transformers.js embedding models
Zero-server architecture using DuckDB-WASM to query static Parquet files
Sanitized and sandboxed email HTML with remote images blocked by default

Use it for

Publishing and exploring FOIA or public-records email archives without a backend server
Searching through large PST and mbox exports using natural language and semantic queries
Hosting static, searchable mailbox dumps on object storage like Cloudflare R2
Exporting raw email datasets to documented Parquet tables for DuckDB, Polars, or pandas analysis

Alternatives to Mailbox Viewer

PixelRAG — Preserves visual structure like tables and charts that text parsers miss.
AI Toolbox — Organize, search, and export chats across four major AIs in one place.
Hister — Protects privacy with a self-hosted search index for your pages and files.
Instant — Finds files using semantic descriptions without sending any data to the cloud.
Glossdex — It returns accurate results and shows nothing when data is missing.
Anygrep — Runs locally on the CPU using EmbeddingGemma 2 without sending data away.
Jina — It provides reliable reader and search APIs optimized for LLMs and RAG systems.
MemFree — It combines hybrid web search with AI summarization and page generation.
DigUp — It searches local files by content and meaning without sending data to the cloud.
Bright Data MCP — Provides an MCP server with access to proxy infrastructure and scraping APIs.

All Mailbox Viewer alternatives