E-mail · Calendar & contacts · Sending e-mail from apps
Stalwart Mail Server
Modern all-in-one mail server: IMAP, JMAP, SMTP, calendars.
open source self-hostable Stalwart Labs · GBA single, fast mail server with spam filtering, CalDAV/CardDAV and a web admin; built in the UK, written in Rust.
Website ↗ Source ↗ Plan “E-mail” with itPlan “Calendar & contacts” with itPlan “Sending e-mail from apps” with it
How you can run it
| Way | Where the data lives | Price basis | Verdict |
|---|---|---|---|
| Host it myself | your own server or hardware | free | green — You run it yourself: no data leaves your own infrastructure. |
Facts
| Company / project | Stalwart Labs (GB) |
|---|---|
| Licence | AGPL-3.0 |
| Self-hosting footprint | 512 MB RAM · 0.5 vCPU · 10 GB — small deployment: a household or a team of up to ~20 people |
| Commonly replaces | Google Workspace, Microsoft 365 |
| Upstream (awesome-selfhosted-data) | 14,512 stars · updated 2026-09-03 · Rust, Docker |
| Provenance | curated, verified 2026-09-04 |
Machine-readable: /api/tools/stalwart.json. Something wrong? Tell us.