Fast and efficient
Optimized for high-speed email processing with a lean, async core.
Open-source SMTP relay
Blazing fast.
Brutally lean.▋
Hedwig is a high-performance, minimalist SMTP server implemented in Rust. It receives, queues, and forwards email to destination SMTP servers using a durable on-disk queue and a straightforward configuration.
Core capabilities
Focused on SMTP relay, nothing extra.
Minimalist design
Focuses on core SMTP relay flows without unnecessary complexity.
Persistent queue
Emails are queued on the filesystem for durable processing.
Forward-only
Specializes in receiving and forwarding, not full server semantics.
Security features
Supports DKIM, TLS, and SMTP authentication with practical defaults.
Rate limiting
Per-domain rate limiting keeps outbound delivery healthy.
Get mail flowing.
Download a release binary, write one config file, and Hedwig is relaying.