~14,800 stars · Dual: AGPL-3.0 and Stalwart Enterprise License v2 (SELv2), read from the repository page; the LICENSE file returned HTTP 404 from this sandbox · v0.16.23 (2026-09-21) · Track this in Scout
A complete mail server with calendars and contacts in one program, speaking SMTP, IMAP, JMAP, CalDAV, CardDAV and WebDAV.
▶Repo detailsthe review · specs · pros & cons · install
What it is
Stalwart is a mail server that speaks SMTP, IMAP, JMAP, CalDAV, CardDAV and WebDAV in one binary (a binary is a single compiled program file you run directly). It replaces the usual stack of Postfix, Dovecot, Rspamd and a separate calendar server.
What it is good for. Anyone who wants mail on a domain of their own without renting a mailbox per person, and who has looked at a classic mail stack and decided it was too many moving parts. It suits a small team, a family domain, or an application that needs to receive mail reliably. It is also the easiest way to get shared calendars and contacts without a separate groupware install.
- One program instead of five. One configuration file, one upgrade, one thing to monitor.
- Spam filtering, DKIM and DMARC signing, and full-text search over mailboxes are built in rather than added.
- Calendars and contacts come with it, so phones and desktop mail apps sync without a second server.
- Dual-licensed: AGPL-3.0 for the open parts and the Stalwart Enterprise License v2 for the rest, as stated on the repository page. The licence file itself could not be opened from here, so read it before building anything commercial on it.
- Running any mail server is the hard part, not installing it. Reverse DNS, SPF, DKIM, DMARC and a clean sending address all have to be right, or large providers will quietly discard the mail.
- It is at version 0.16.23 and has not reached 1.0. Configuration keys have moved between minor versions, so upgrades need reading, not just pulling.
- docker-mailserver/docker-mailserver
18,747 stars, the classic stack packaged into one container; more proven in the field, and still several programs under the lid.
Track this in Scout - mailcow/mailcow-dockerized
13,273 stars, a full suite with a web interface for managing domains and mailboxes; the friendliest to administer and the heaviest to run.
Track this in Scout - foxcpp/maddy
6,043 stars, the same single-program idea in Go and deliberately smaller; no calendars, no contacts, no web interface.
Track this in Scout
mkdir -p /opt/stalwart/data docker run -d --name stalwart \ -p 443:443 -p 25:25 -p 587:587 -p 993:993 \ -v /opt/stalwart/data:/opt/stalwart \ --restart unless-stopped \ stalwartlabs/stalwart:latest
