# Stalwart

Stalwart is an open-source, all-in-one email server that unifies JMAP, IMAP (Internet Message Access Protocol), and SMTP (Simple Mail Transfer Protocol) in a single self-contained package. It is open source and self-hosted, installable on Docker Hub, Proxmox, ZimaOS, TrueNAS, Unraid and Umbrel.

Canonical page: https://ourlocalhost.com/app/813/stalwart

## Description

Stalwart is an open-source, all-in-one email server that unifies JMAP, IMAP (Internet Message Access Protocol), and SMTP (Simple Mail Transfer Protocol) in a single self-contained package. It lets homelabbers and small teams self-host secure, fast, and scalable mail and collaboration services without stitching together separate components.

## Platform availability

Available on 5 of 9 platforms: Unraid, TrueNAS, Umbrel, ZimaOS, Proxmox.

## Health score

39/100 (Low), based on 3 of 4 factors.
- Maintained: 0 (GitHub repository no longer exists)
- Easy to install: 75 (5 install platforms, install notes, Docker image)
- Light to run: 95 (512 MB minimum RAM, runs on ARM)

## Links

- Docker Hub: https://hub.docker.com/r/stalwartlabs/stalwart
- Official website: https://stalw.art/
- GitHub: https://github.com/stalwartlabs/stalwart
- Proxmox: https://community-scripts.github.io/ProxmoxVE/scripts?id=stalwart
- ZimaOS: https://github.com/bigbeartechworld/big-bear-casaos/tree/master/Apps/stalwart-mail
- TrueNAS: https://apps.truenas.com/catalog/stalwart/
- Unraid: https://ca.unraid.net/apps/stalwart-1e4sdnm0ber4nq?q=stalwart
- Umbrel: https://apps.umbrel.com/app/stalwart

## Common questions

### Will existing mail and calendar clients work with Stalwart?

Yes. It natively supports JMAP, IMAP, POP3, SMTP, CalDAV, CardDAV, and WebDAV.

### Do I need a separate anti-spam system for Stalwart?

No. Stalwart includes spam and phishing protection with a statistical filter, public blocklists, sender reputation, and AI-driven analysis, and it does not require an extra daemon.

### Can Stalwart serve email, calendars, contacts, and shared files from one server?

Yes. It provides mail plus CalDAV, CardDAV, and WebDAV for calendars, contacts, and shared files in the same server.

### Can Stalwart be run as a multi-node deployment?

Yes. It can run as one node or as a cluster across regions.

## Alternatives

- Postfix: Postfix is a mail transfer agent (MTA) that routes and delivers electronic mail.
- docker-mailserver: A production-ready, full-featured mail server that runs in a single Docker container, bundling SMTP, IMAP, LDAP, anti-spam, antivirus, and…
- mailcow: dockerized: mailcow is a mail server suite based on Dovecot, Postfix, SOGo, Rspamd and other open source software, that provides a modern Web UI for ad…

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Source: Our Local Host (https://ourlocalhost.com/app/813/stalwart), the self-hosted and open-source app directory.