PSTInsight

A fast, modern viewer for Microsoft Outlook PST files — no Outlook, no MAPI, no COM. PSTInsight reads the on-disk PST format directly and renders it in a clean three-pane desktop UI.

This is a ground-up Rust rewrite of the original C#/WPF PSTInsight, built on Tauri with a React + TypeScript front end and the pst-parse parsing engine.

Features

• Folder tree with content and unread counts.
• Virtualized message list — folders with tens of thousands of messages stay responsive because the list is painted from the folder's contents table, not by opening every message.
• Reading pane with sender/recipient headers, dates, and the message body. HTML bodies render in a fully sandboxed iframe (DOMPurify-sanitized, a per-frame CSP, and remote images blocked by default with an opt-in "Load images" button — like a real mail client).
• Attachments: save by-value attachments to disk; embedded messages save as .eml. Bytes stream straight to disk and are never shipped to the UI.
• Export a single message or an entire folder to EML, TXT, or MSG (.msg is written as a real MS-OXMSG compound file).
• Search across all folders by subject/sender, with an optional (slower) body search.

Architecture

PSTInsight/
├── pst-parse/ # Pure-Rust, read-only PST parser (no Outlook/MAPI)
├── src-tauri/ # Tauri backend: state, IPC commands, exporters
│ └── src/
│ ├── commands.rs # IPC surface (open, list, get, export, search…)
│ ├── dto.rs # Serializable DTOs for the UI (no domain leakage)
│ ├── export.rs # EML/TXT rendering + format dispatch
│ ├── msg.rs # MS-OXMSG (.msg) compound-file writer
│ └── state.rs # Shared open-PST state
└── src/ # React + TypeScript + Tailwind UI
├── components/ # FolderTree, MessageList, MessagePreview, HtmlBody…
└── lib/ # Typed IPC client and formatting helpers

Design notes:

• Parsing runs on a blocking worker thread so a large PST never stalls the UI.
• The list view uses pst_parse::Pst::message_summaries, which reads the contents table directly — dramatically cheaper than opening each message.
• Untrusted email HTML is treated as hostile: sanitized, sandboxed, and remote-blocked before it ever renders.

Development

Prerequisites: Node 20+, Rust (pinned in rust-toolchain.toml), and the Tauri prerequisites for your OS.

npm install
npm run tauri dev # run the app with hot-reload
npm run tauri build # produce a release build + installer

Quality gates:

cargo clippy --all-targets -- -D warnings # in pst-parse and src-tauri
cargo test# parser + MSG round-trip tests

Limitations

• Unicode PSTs only. ANSI (32-bit, Outlook 97–2002) files are rejected with a clear error; cyclic-encrypted blocks are likewise unsupported (both inherited from pst-parse).
• Read-only: PSTInsight never modifies the source file.
• .msg export covers standard message/recipient/attachment properties; named properties are emitted as an (empty) map.

License

MIT.