15 Top Open Source Email Servers for postmarket OS in 2025
The 15 top free and open-source email servers for postmarket OS with setup guides, tutorials, videos, and instructions.
Email Server Screenshots
Forward Email
- IMAP
- SMTP
- MX
- SQLite Encrypted
Forward Email is an open-source email server for postmarket OS. The official description from its website says, "Privacy-focused encrypted email for you. We are the go-to email service for hundreds of thousands of creators, developers, and businesses. Send and receive email as you@yourdomain.com with your custom domain or use one of ours."
Docker Mailserver
- IMAP
- SMTP
- MX
- SQLite Encrypted
Docker Mailserver is an open-source email server for postmarket OS. The official description from its website says, "docker-mailserver, or DMS for short, is a production-ready fullstack but simple mail server (SMTP, IMAP, LDAP, Antispam, Antivirus, etc.)."
Maddy Mail Server
- IMAP
- SMTP
- MX
- SQLite Encrypted
Maddy Mail Server is an open-source email server for postmarket OS. The official description from its website says, "Maddy Mail Server implements all functionality required to run a e-mail server."
Mail-in-a-Box
- IMAP
- SMTP
- MX
- SQLite Encrypted
Mail-in-a-Box is an open-source email server for postmarket OS. The official description from its website says, "Take back control of your email with this easy-to-deploy mail server in a box."
mailcow
- IMAP
- SMTP
- MX
- SQLite Encrypted
mailcow is an open-source email server for postmarket OS. The official description from its website says, "mailcow: dockerized is an open source groupware/email suite based on docker."
Dovecot
- IMAP
- SMTP
- MX
- SQLite Encrypted
Dovecot is an open-source email server for postmarket OS. The official description from its website says, "Dovecot is an excellent choice for both small and large installations."
WildDuck
- IMAP
- SMTP
- MX
- SQLite Encrypted
WildDuck is an open-source email server for postmarket OS. The official description from its website says, "WildDuck is a modern mail server software for IMAP and POP3."
Exim
- IMAP
- SMTP
- MX
- SQLite Encrypted
Exim is an open-source email server for postmarket OS. The official description from its website says, "Exim is a message transfer agent (MTA) originally developed at the University of Cambridge for use on Unix systems connected to the Internet."
Postfix
- IMAP
- SMTP
- MX
- SQLite Encrypted
Postfix is an open-source email server for postmarket OS. The official description from its website says, "It is Wietse Venema's mail server that started life at IBM research as an alternative to the widely-used Sendmail program."
chasquid
- IMAP
- SMTP
- MX
- SQLite Encrypted
chasquid is an open-source email server for postmarket OS. The official description from its website says, "chasquid is an SMTP (email) server with a focus on simplicity, security, and ease of operation."
Haraka
- IMAP
- SMTP
- MX
- SQLite Encrypted
Haraka is an open-source email server for postmarket OS. The official description from its website says, "A modern, high performance, flexible SMTP server."
Postal
- IMAP
- SMTP
- MX
- SQLite Encrypted
Postal is an open-source email server for postmarket OS. The official description from its website says, "Postal is a complete and fully featured mail server for use by websites & web servers."
ZoneMTA
- IMAP
- SMTP
- MX
- SQLite Encrypted
ZoneMTA is an open-source email server for postmarket OS. The official description from its website says, "ZoneMTA provides granular control over routing different messages. "
keila
- IMAP
- SMTP
- MX
- SQLite Encrypted
keila is an open-source email server for postmarket OS. The official description from its website says, "Open Source Newsletter Tool."
listmonk
- IMAP
- SMTP
- MX
- SQLite Encrypted
listmonk is an open-source email server for postmarket OS. The official description from its website says, "Self-hosted newsletter and mailing list manager."
Email Server Comparison
| Name | Description | Screenshot | IMAP | MX | SMTP | SQLite Encrypted | Website | Wikipedia |
|---|---|---|---|---|---|---|---|---|
| Forward Email ⭐ Preferred | Privacy-focused encrypted email for you. We are the go-to email service for hundreds of thousands of creators, developers, and businesses. Send and receive email as you@yourdomain.com with your custom domain or use one of ours. | Screenshot | Yes | Yes | Yes | Yes | Website | |
| Docker Mailserver | docker-mailserver, or DMS for short, is a production-ready fullstack but simple mail server (SMTP, IMAP, LDAP, Antispam, Antivirus, etc.). | Screenshot | Yes | Yes | Yes | No | Website | |
| Maddy Mail Server | Maddy Mail Server implements all functionality required to run a e-mail server. | Screenshot | Yes | Yes | Yes | No | Website | |
| Mail-in-a-Box | Take back control of your email with this easy-to-deploy mail server in a box. | Screenshot | Yes | Yes | Yes | No | Website | Wikipedia |
| mailcow | mailcow: dockerized is an open source groupware/email suite based on docker. | Screenshot | Yes | Yes | Yes | No | Website | |
| Dovecot | Dovecot is an excellent choice for both small and large installations. | Screenshot | Yes | No | No | No | Website | Wikipedia |
| WildDuck | WildDuck is a modern mail server software for IMAP and POP3. | Screenshot | Yes | No | No | No | Website | |
| Exim | Exim is a message transfer agent (MTA) originally developed at the University of Cambridge for use on Unix systems connected to the Internet. | Screenshot | No | Yes | Yes | No | Website | Wikipedia |
| Postfix | It is Wietse Venema's mail server that started life at IBM research as an alternative to the widely-used Sendmail program. | Screenshot | No | Yes | Yes | No | Website | Wikipedia |
| chasquid | chasquid is an SMTP (email) server with a focus on simplicity, security, and ease of operation. | Screenshot | No | Yes | Yes | No | Website | |
| Haraka | A modern, high performance, flexible SMTP server. | Screenshot | No | Yes | No | No | Website | Wikipedia |
| Postal | Postal is a complete and fully featured mail server for use by websites & web servers. | Screenshot | No | Yes | No | No | Website | |
| ZoneMTA | ZoneMTA provides granular control over routing different messages. | Screenshot | No | Yes | No | No | Website | |
| keila | Open Source Newsletter Tool. | Screenshot | No | Yes | No | No | Website | |
| listmonk | Self-hosted newsletter and mailing list manager. | Screenshot | No | Yes | No | No | Website |