Bringing the madness to mail delivery.

Rust chatmail relay for , encrypted, federated, one binary.

Download Quick Start

What is Chatmail?

Chatmail is the protocol for secure, private chat over email. Delta Chat uses it to turn IMAP and SMTP into a fast, encrypted messaging experience, and it works best when both sides use a proper chatmail relay.

Madmail is one implementation of that relay: a Rust rewrite of Madmail v1 with SMTP, IMAP, encryption enforcement, and real-time services built in. It is not a general-purpose mail server It is specialized for how Delta Chat works.

Features

  • SMTP + IMAP Submission, incoming, and retrieval, full stack in one process
  • PGP-only policy Unencrypted mail rejected at the server
  • JIT registration No sign-up flow; accounts created on first auth
  • HTTP federation /mxdeliv for fast inter-server delivery, SMTP as fallback
  • No-Log mode Strip message metadata when strict privacy is required
  • TURN / Iroh Audio/video calls and WebXDC relay, no extra services
  • ACME / TLS Automatic certificate management
  • One binary Admin API, WebIMAP, federation, batteries included

Quick Setup

Download the release binary, then install and start the service:

Also works with a public IP and no domain. See deployment options