Archive every email you've ever sent, then ask AI about it offline

What it does msgvault is a local-first email and SMS archiver written in Go. It downloads complete Gmail accounts, syncs standard IMAP servers, and imports MBOX exports or Apple Mail directories, storing raw MIME, metadata, and SHA-256-deduplicated attachments locally. Once synced, search, analytics, and AI assistant access all run entirely offline against DuckDB, Parquet, and SQLite.

The interesting bit The project treats your mail store as immutable analytics infrastructure. It layers DuckDB over Parquet for millisecond aggregates across hundreds of thousands of messages, surfaces them in an interactive TUI, and exposes the archive to Claude Desktop via an MCP server. Optional vector search plugs into self-hosted Ollama or llama.cpp endpoints for semantic or hybrid BM25-plus-vector retrieval.

Key highlights

• Full offline operation after initial sync: no network needed for search, stats, or MCP queries
• Supports Gmail, IMAP, MBOX, Apple Mail .emlx, and Android SMS Backup & Restore XML
• Content-addressed attachments deduplicated by SHA-256 across multiple accounts
• Optional semantic and hybrid search via local OpenAI-compatible embedding endpoints
• Daemon mode with HTTP API and cron-style scheduled syncs for headless or NAS use

Caveats

• Explicitly alpha: APIs, storage formats, and CLI flags may change without notice
• Gmail requires creating your own Google Cloud OAuth credentials before first use
• Building from source needs Go 1.25+ and a C/C++ compiler for CGO to statically link DuckDB

Verdict Worth a look if you believe your mail corpus should be queryable local data rather than a cloud-hosted liability. Skip it if you treat OAuth setup as a dealbreaker or need production-grade stability today.