Mbox Viewer – Fast native macOS app for reading MBOX files

Summary: Mbox Viewer is a native macOS app that opens, searches, and exports emails from MBOX and EML files, including large Gmail Takeout archives. It uses a streaming parser to index files once, enabling instant re-opening and label browsing offline.

What it does

It parses and indexes MBOX and EML archives using a streaming method, supports Gmail labels via X-Gmail-Labels headers, and offers Gmail-like search syntax for efficient offline email access.

Who it's for

Users needing a fast, reliable way to read and search large Gmail backups or email archives on Mac without importing or heavy clients.

Why it matters

It solves the slow, unreliable, or resource-heavy experience of accessing large MBOX files after Google Takeout exports.