Bichon

Bichon is an open-source, self-hosted email archiving server built in Rust. It downloads emails from IMAP accounts to build a full-text search index, providing a centralized repository for long-term preservation and programmatic access to archived messages. It functions as an archiver rather than an email client, meaning it does not send, compose, forward, or reply to emails.

The software is deployed as a server with an embedded WebUI and a REST API. It can be run as a standalone binary on Linux, macOS, and Windows, or deployed via Docker and Docker Compose. Users manage their archives through the browser-based interface or via a command-line interface for importing and exporting data, while an optional embedded SMTP server allows the system to receive emails directly at the gateway level.

Key features

• Multi-account IMAP downloads with support for password and OAuth 2.0 authentication
• Full-text search across subjects, bodies, senders, and attachment properties
• Incremental fetching using UID-based delta downloads to capture only new messages
• Content deduplication using BLAKE3 hashing for email bodies and attachments
• Role-based access control with five built-in roles and granular permissions
• CLI tools for importing EML, MBOX, Thunderbird profiles, and Outlook PST files
• Embedded SMTP server for receiving emails directly at the gateway level
• Scheduled synchronization using cron expressions for per-account downloads
• Three-layer embedded storage using Tantivy, Fjall, and memdb with no external dependencies

Bichon uses a specialized storage architecture to handle data without requiring external database installations. It employs Zstd and LZ4 compression to optimize disk usage and implements account-level isolation to ensure users only access authorized data. The system includes an OpenAPI 3.0 compliant API, providing interactive documentation via Swagger UI, ReDoc, and Scalar for programmatic retrieval of archived content. To protect privacy, the WebUI blocks external images and tracking pixels by default, requiring users to selectively allow remote content on a per-message basis.

This application is designed for users and organizations requiring a permanent, searchable record of email communications across multiple accounts with a focus on digital preservation.