18 self-hosted Twake Mail alternatives

Production-ready mail server stack in a Docker container with SMTP, IMAP/POP3, LDAP auth, anti-spam/AV, DKIM/DMARC, and optional OAuth2 support.

18.8k stars2k forksMITlast commit 24 Aug 2026Actively maintained

Mail-in-a-Box is a one-click mail server appliance for Ubuntu, bundling SMTP/IMAP, webmail, DNS, TLS automation, backups, and an admin control panel.

15.4k stars1.5k forksCC0-1.0last commit 21 Aug 2026Actively maintained

All-in-one open-source mail and collaboration server with SMTP, IMAP, JMAP, CalDAV, CardDAV, and WebDAV, plus integrated anti-spam and phishing protection.

14.4k stars909 forkslast commit 25 Aug 2026Actively maintained

Mailcow is a dockerized mail server suite providing SMTP/IMAP, webmail, anti-spam/anti-virus, and domain/mailbox administration via a unified web UI.

13.3k stars1.8k forksGPL-3.0last commit 18 Aug 2026Actively maintained

All-in-one secure mail server with SMTP, IMAP, webmail, automatic TLS (ACME), and built-in SPF/DKIM/DMARC plus junk filtering for low-maintenance domains.

5.8k stars218 forksMITlast commit 23 Aug 2026Actively maintained

Modoboa is an open source mail server management platform with a modern web UI, integrating Postfix and Dovecot with admin tools, webmail, calendar, and address book.

3.5k stars481 forksISClast commit 26 Aug 2026Actively maintained

A Bash script that auto-implements a full mail server (Postfix, Dovecot, DKIM, SpamAssassin) with TLS and PAM-based logins on Debian/Ubuntu.

2.2k stars341 forksGPL-3.0last commit 4 May 2025Slowing down

Open source groupware suite providing webmail, calendaring, address books, and shared resources via open standards like IMAP, CalDAV, and CardDAV.

2.2k stars320 forksGPL-2.0last commit 13 Aug 2026Actively maintained

WildDuck is a horizontally scalable IMAP/POP3 mail server that stores all mail in MongoDB, runs stateless Node.js workers, and provides a REST API for full server control.

2.1k stars278 forksEUPL-1.2last commit 26 Aug 2026Actively maintained

Automated open-source mail server installer bundling Postfix, Dovecot, webmail, anti-spam/antivirus and LDAP/SQL backends for mainstream Linux/BSD.

1.8k stars260 forksGPL-3.0last commit 27 Aug 2026Actively maintained

High-performance, standards-compliant IMAP/POP3/LMTP server with flexible authentication, extensible plugin system (Lua, Sieve) and OpenSSL TLS support.

1.2k stars347 forkslast commit 24 Aug 2026Actively maintained

Open-source PHP groupware providing CalDAV/CardDAV, ActiveSync, email client, CRM, tasks, file manager and Docker images for on-premise collaboration.

21 stars4 forksAGPL-3.0last commit 26 Aug 2026Actively maintained

Open-source webmail and groupware offering email, contacts, calendar, cloud drive, tasks, notes and an admin control panel for multi-tenant email services.

Activity unknown

Lightweight SMTP server written in Go that receives and sends email via a single JSON config and executable hooks; supports per-user DKIM and TLS.

Activity unknown

Open Source Sendmail provides a subset of Proofpoint's Sendmail Sentrion MTA for large-scale mail deployments; current release is 8.16.1 with a PGP-signed tarball and OpenDKIM integration.

Activity unknown

Courier is an integrated mail server suite providing ESMTP (MTA), IMAP, POP3, webmail, and mailing lists with optional LDAP/MySQL/PostgreSQL-backed virtual accounts.

Activity unknown

Simple NixOS Mailserver provides NixOS modules to deploy a full email server with SMTP/IMAP, spam filtering, DKIM/DMARC/SPF, and TLS automation.

Activity unknown

Self-hosted enterprise collaboration suite providing email, webmail, calendaring, contacts, and administration for organizations.

Activity unknown