Self-hosted Email Servers (SMTP/IMAP) tools

44 open source alternatives in this category

44 services found

docker-mailserver logo

docker-mailserver

Containerized mail server stack for SMTP and IMAP with anti-spam

18.8k
2k
Last commit

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

MITActively maintained
Alternative to:
Gmail logo
Gmail
+16
Postal logo

Postal

Open source mail delivery platform for inbound and outbound email

16.8k
1.3k
Last commit

Postal is an open source mail delivery platform for sending and receiving email, with SMTP support, web-based management, and tools for running your own SendGrid-style service.

MITActively maintained
Alternative to:
SendGrid logo
SendGrid
+10
Mail-in-a-Box logo

Mail-in-a-Box

Turnkey email server with webmail, DNS, TLS, and admin panel

15.4k
1.5k
Last commit

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.

CC0-1.0Actively maintained
Alternative to:
Microsoft Exchange Online logo
Microsoft Exchange Online
+15
Stalwart Mail Server logo

Stalwart Mail Server

All-in-one mail and collaboration server for modern and legacy protocols

14.4k
909
Last commit

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

Actively maintained
Alternative to:
Microsoft Exchange Online logo
Microsoft Exchange Online
+19
mailcow: dockerized logo

mailcow: dockerized

Docker-based email server suite with a web admin interface

13.3k
1.8k
Last commit

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

GPL-3.0Actively maintained
Alternative to:
Microsoft Exchange Online logo
Microsoft Exchange Online
+16
Mailu logo

Mailu

Docker-based mail server with webmail and admin interface

7.5k
997
Last commit

Mailu is a full-featured mail server distributed as Docker images, providing SMTP/IMAP/POP3, webmail, administration UI, and built-in security and anti-spam features.

Actively maintained
Alternative to:
Microsoft Exchange Online logo
Microsoft Exchange Online
+19
SimpleLogin logo

SimpleLogin

Open-source email aliasing and forwarding service

7k
649
Last commit

SimpleLogin is an open-source email alias service that lets you create aliases to protect your real inbox, forward mail, and reply or send from aliases using custom domains.

AGPL-3.0Actively maintained
Alternative to:
SimpleLogin logo
SimpleLogin
+3

Maddy Mail Server

Composable all-in-one SMTP/IMAP mail server with security features

6.1k
326
Last commit

Go-based, modular mail server implementing SMTP/LMTP/IMAP with built-in DKIM/SPF/DMARC, storage backends (SQLite/Postgres/S3), Prometheus metrics and Docker support.

GPL-3.0Actively maintained
Alternative to:
Microsoft Exchange Online logo
Microsoft Exchange Online
+10

Mox

Modern, secure, all-in-one mail server for self-hosted email

5.8k
218
Last commit

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.

MITActively maintained
Alternative to:
Microsoft Exchange Online logo
Microsoft Exchange Online
+19
Haraka logo

Haraka

High-performance, extensible SMTP server built on Node.js

5.6k
712
Last commit

Haraka is a fast, event-driven SMTP server for receiving, filtering, and relaying email, featuring a modular plugin architecture for customization at scale.

MITActively maintained
Alternative to:
Postfix logo
Postfix
+11
AnonAddy logo

AnonAddy

Anonymous email aliasing and forwarding with GPG support

4.8k
267
Last commit

Open-source anonymous email forwarding that creates and manages aliases, supports custom domains, encrypted forwarding, and self-hosting via Postfix and MariaDB.

AGPL-3.0Actively maintained
Alternative to:
Addy.io (AnonAddy) logo
Addy.io (AnonAddy)
+3
Modoboa logo

Modoboa

Mail hosting and management platform with web UI and webmail

3.5k
481
Last commit

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.

ISCActively maintained
Alternative to:
Microsoft Exchange Online logo
Microsoft Exchange Online
+16
AliasVault logo

AliasVault

End-to-end encrypted password manager with built-in email aliasing

3.1k
104
Last commit

Privacy-first, end-to-end encrypted password and email alias manager with passkeys, TOTP, apps and extensions, plus a built-in email server for self-hosting.

AGPL-3.0Actively maintained
Alternative to:
SimpleLogin logo
SimpleLogin
+12
YunoHost logo

YunoHost

Debian-based server OS and web control panel for self-hosted apps

3k
351
Last commit

Open-source Debian-based OS and control panel that simplifies installing, managing and securing web apps, mail and services via a web admin and app catalog.

AGPL-3.0Actively maintained
Alternative to:
Cloudron logo
Cloudron
+19
emailwiz logo

emailwiz

Bash-based installer that deploys a secure Debian/Ubuntu mail server stack.

2.2k
341
Last commit

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

GPL-3.0Slowing down
Alternative to:
Microsoft Exchange Online logo
Microsoft Exchange Online
+14
WildDuck logo

WildDuck

Scalable IMAP/POP3 mail server with MongoDB backend and REST API

2.1k
278
Last commit

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.

EUPL-1.2Actively maintained
Alternative to:
Microsoft Exchange Online logo
Microsoft Exchange Online
+13
iRedMail logo

iRedMail

Open-source full-featured mail server stack for Linux/BSD

1.8k
260
Last commit

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

GPL-3.0Actively maintained
Alternative to:
Microsoft Exchange Online logo
Microsoft Exchange Online
+16
Dovecot logo

Dovecot

Secure IMAP, POP3 and LMTP server and email storage backend

1.2k
347
Last commit

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

Actively maintained
Alternative to:
Microsoft Exchange Online logo
Microsoft Exchange Online
+15

OpenTrashmail

Self-hosted disposable email inbox with web UI, API, RSS, webhooks

924
75
Last commit

OpenTrashmail is a standalone disposable email (“trashmail”) service with its own SMTP server, offering a web UI plus JSON API, RSS feeds, and webhooks for received mail.

Apache-2.0Slowing down
Alternative to:
Mailinator logo
Mailinator
+3
Hyvor Relay logo

Hyvor Relay

Open-source, self-hosted Email API for developers

876
59
Last commit

AGPL-3.0 open-source email API for developers that can be self-hosted; supports SMTP sending, webhooks, DNS automation, observability, multi-tenancy, and project isolation.

AGPL-3.0Actively maintained
Alternative to:
Amazon Simple Email Service (Amazon SES) logo
Amazon Simple Email Service (Amazon SES)
+11
DavMail logo

DavMail

Exchange and Microsoft 365 gateway for standard mail and PIM protocols

752
108
Last commit

DavMail is a Java gateway that lets standard clients use IMAP/POP/SMTP, CalDAV, CardDAV, and LDAP with Microsoft Exchange and Microsoft 365 via OWA/EWS.

GPL-2.0Actively maintained
Alternative to:
Proton Mail Bridge logo
Proton Mail Bridge
Nortix Mail logo

Nortix Mail

Disposable email server with a simple self-hosted setup

713
55
Last commit

Self-hosted disposable email server for creating temporary addresses to reduce spam and protect privacy, with an optional TLS setup and a web UI.

Actively maintained
Alternative to:
Mailinator logo
Mailinator
+3

Cyrus IMAP

Email, contacts, and calendar server with IMAP and JMAP

643
175
Last commit

Cyrus IMAP is a secure, scalable mail server providing IMAP/JMAP email plus CalDAV/CardDAV contacts and calendars, with ACLs, quotas, search, and replication.

Actively maintained
Alternative to:
Microsoft Exchange Online logo
Microsoft Exchange Online
+18
Piler logo

Piler

Open-source email archiving and eDiscovery platform

341
50
Last commit

Scalable email archiving solution with tamper-evident retention, full-text search, legal hold, deduplication and access controls for compliance.

Actively maintained
Alternative to:
MailStore Server logo
MailStore Server
+1
Sympa logo

Sympa

Open-source mailing list management software

312
144
Last commit

Open-source mailing list manager for automating subscriptions, moderation, archives and message distribution with web, CLI and SOAP interfaces for large lists.

GPL-2.0Actively maintained
Alternative to:
Groups.io logo
Groups.io

DragonFly Mail Agent (dma)

Lightweight Mail Transfer Agent for local delivery and relay

263
59
Last commit

A small, C-based Mail Transfer Agent for local submission and outbound relay with TLS/SMTP authentication, aimed at home and small office use.

Likely dormant
Alternative to:
Postfix logo
Postfix
+11
HomeServerHQ logo

HomeServerHQ

All-in-one home server platform with VPN, email, and relay

69
7
Last commit

Integrated installer and platform for home infrastructure. Provides VPN relay for NAT traversal, preconfigured email, automatic HTTPS, reverse proxy, and a web management utility.

GPL-3.0Actively maintained
Alternative to:
Cloudron logo
Cloudron
+19
Citadel logo

Citadel

Groupware server with email, calendaring, contacts, and web access

Citadel is an open source groupware and messaging server providing email, calendars, contacts, and a web interface with room-based collaboration.

Activity unknown
Alternative to:
Microsoft Exchange Online logo
Microsoft Exchange Online
+19
Courier Mail Server (Courier MTA) logo

Courier Mail Server (Courier MTA)

Integrated mail server suite with SMTP, IMAP, POP3 and webmail

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
Alternative to:
Microsoft Exchange Online logo
Microsoft Exchange Online
+14
Dovel logo

Dovel

Simple Go-based SMTP server for receiving and sending mail

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
Alternative to:
Amazon Simple Email Service (Amazon SES) logo
Amazon Simple Email Service (Amazon SES)
+11