# Private and open-source alternatives to Microsoft Exchange Server

Also covers Exchange.

1. [Stalwart](https://privacyratings.com/mail-server-software/stalwart-mail-server/): A (100/100). Self-hosted mail and collaboration server written in Rust, with JMAP, IMAP, POP3, SMTP, CalDAV, CardDAV and WebDAV support, built-in spam filtering and a web admin interface.
2. [Dovecot](https://privacyratings.com/mail-server-software/dovecot/): A (90/100). IMAP and POP3 server for Linux and Unix that stores and serves mailboxes, with support for Sieve filtering through Pigeonhole. The Community Edition is open source.
3. [Forward Email](https://privacyratings.com/mail-server-software/forward-email/): B (85/100). Self-hosted version of the Forward Email service, installed with a script that deploys Docker containers. It includes MX, SMTP, IMAP, POP3, CalDAV and CardDAV servers, encrypted SQLite mailboxes, a web interface and optional backups to S3-compatible storage.
4. [Docker Mailserver](https://privacyratings.com/mail-server-software/docker-mailserver/): B (80/100). Self-hosted mail server in a single Docker container, with SMTP, IMAP, POP3, spam and virus filtering, configured through files and environment variables.
5. [iRedMail](https://privacyratings.com/mail-server-software/iredmail/): B (80/100). Installer script that sets up a complete mail server on Linux or BSD from open-source components such as Postfix, Dovecot, Roundcube and SpamAssassin.
6. [Maddy](https://privacyratings.com/mail-server-software/maddy/): B (80/100). All-in-one mail server written in Go that replaces Postfix, Dovecot and OpenDKIM with a single daemon, handling SMTP, IMAP, DKIM, SPF, DMARC, DANE and MTA-STS.
7. [Mail-in-a-box](https://privacyratings.com/mail-server-software/mail-in-a-box/): B (80/100). Self-hosted mail server setup for a single Ubuntu machine, with SMTP, IMAP, webmail, contacts, calendar, spam filtering and backups preconfigured.
8. [mailcow](https://privacyratings.com/mail-server-software/mailcow/): B (80/100). Self-hosted mail server suite based on Docker, with SMTP, IMAP, the SOGo webmail and groupware, spam filtering and a web admin interface.
9. [Mailu](https://privacyratings.com/mail-server-software/mailu/): B (80/100). Self-hosted mail server built from Docker containers, with SMTP, IMAP, webmail, spam and virus filtering and a web admin interface.
10. [Mox](https://privacyratings.com/mail-server-software/mox/): B (80/100). Mail server written in Go for low-maintenance self-hosting, combining SMTP, IMAP, webmail, SPF, DKIM, DMARC, MTA-STS, automatic TLS and spam filtering in one program.
11. [Postfix](https://privacyratings.com/mail-server-software/postfix/): B (80/100). Mail transfer agent that routes and delivers email over SMTP, used on many Linux and Unix servers as the default mail server.
12. [Modoboa](https://privacyratings.com/mail-server-software/modoboa/): C (65/100). Self-hosted mail hosting and management platform built on Postfix and Dovecot, with a web admin interface, webmail, calendars, contacts and spam filtering.

Source: https://privacyratings.com/alternatives/microsoft-exchange-server/