Hedwig

Hedwig - A high-performance, minimalist SMTP server implemented in Rust.

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Features

• Async SMTP relay with persistent filesystem queue
• DKIM signing (RSA and Ed25519)
• MTA-STS (RFC 8461) — automatic TLS policy enforcement for outbound delivery
• SMTP authentication (PLAIN, LOGIN, CRAM-MD5; multiple users)
• TLS/STARTTLS support with multiple listeners
• Per-domain rate limiting
• Prometheus metrics and health checks
• Domain-based sender/recipient filtering

Docs

Documentation lives at https://hedwig-mail.dev

Install (recommended)

Download the latest release binary from GitHub Releases:

curl -L -o hedwig.zip https://github.com/iamd3vil/hedwig/releases/download/v0.12.3/hedwig-v0.12.3-linux-x86_64.zip
unzip hedwig.zip
chmod +x hedwig

Checksums:

https://github.com/iamd3vil/hedwig/releases/download/v0.12.3/checksums.txt

Docker

Images are published at ghcr.io/iamd3vil/hedwig for Linux AMD64 and ARM64. Docker selects the matching architecture automatically:

docker pull ghcr.io/iamd3vil/hedwig:0.12.3

Use an exact version for a pinned deployment. The 0.12 and latest tags are updated by release builds. See the Docker quickstart for configuration and persistent storage mounts, and the release workflow guide for publishing.

Build from source

git clone https://github.com/iamd3vil/hedwig.git
cd hedwig
cargo build --release

License

AGPL v3. See LICENSE.