# Self-Hosted Email - webcentive

Source: https://www.webcentive.com/selfhostemail/  
Format: Markdown version of the HTML page (same content, lookups and page chrome left out).

Open-source and commercial email servers you run on your own machines (on-premises or a VPS you control). Mail still travels over ordinary SMTP rather than a peer-to-peer network. A typical setup needs a static IP address, reverse DNS (rDNS) that matches the mail hostname, SPF, DKIM and DMARC records, and port 25 open; many residential ISPs block that port.  

More on webcentive: [free email](https://www.webcentive.com/free_email.html) | [decentralized messaging](https://www.webcentive.com/decentralizedmessaging/) | [DNS tools](https://www.webcentive.com/dnstools/) | [domains](https://www.webcentive.com/shopdomains/shopdomains.html) | [software](https://www.webcentive.com/software/software.html)  

Each site has quick lookups: who owns it (whois), its history (Wayback Machine), a safety check, and one-tap questions to AI helpers. Grok asks you to tap Send first.  
Links last checked Nov 13, 2026. License, first-release year, latest activity and language below were checked the same day.  

**License, age, maintenance and language**

The table below covers every server listed on this page: whether it is open source, the year of its first public release, the latest release or commit we could verify on Nov 13, 2026, and the main language of the project. Facts come from official sites or project repositories, with a light link to the source. Where a fact is not published, that is stated rather than guessed. Several open-source suites are installers or Docker stacks around Postfix and Dovecot rather than new mail engines.

| Server | License | First release | Latest activity | Language |
| --- | --- | --- | --- | --- |
| **Open source** | | | | |
| [docker-mailserver](https://docker-mailserver.github.io/docker-mailserver/latest/) | [MIT](https://github.com/docker-mailserver/docker-mailserver/blob/master/LICENSE) | [2015](https://tvi.al/simple-mail-server-with-docker/) | [v17.0.0, Nov 5, 2026](https://github.com/docker-mailserver/docker-mailserver/releases/tag/v17.0.0) | Shell (wraps Postfix and Dovecot, which are C) |
| [Dovecot](https://dovecot.org/) | [LGPL-2.1 / MIT](https://github.com/dovecot/core/blob/main/COPYING) | [2002](https://dovecot.org/) | [2.4.5, Aug 28, 2026](https://github.com/dovecot/core/releases/tag/2.4.5) | C |
| [hMailServer](https://www.hmailserver.com/) | [AGPL-3.0](https://www.hmailserver.com/) | [2002](https://www.hmailserver.com/documentation/latest/whatis_hmailserver/) | [5.7.2 (build 3164), Nov 13, 2026](https://www.hmailserver.com/download) | C++ / C# |
| [iRedMail](https://www.iredmail.org/) | [GPL-3.0](https://github.com/iredmail/iRedMail/blob/master/LICENSE) | [2007](https://www.iredmail.org/) | [1.8.10, Nov 9, 2026](https://github.com/iredmail/iRedMail/releases/tag/1.8.10) | Shell (installer for Postfix, Dovecot and other components) |
| [Maddy](https://maddy.email/) | [GPL-3.0](https://github.com/foxcpp/maddy/blob/master/COPYING) | [2020](https://github.com/foxcpp/maddy/releases/tag/v0.1.0) | [v0.9.7, Nov 5, 2026](https://github.com/foxcpp/maddy/releases/tag/v0.9.7) | Go |
| [mailcow](https://mailcow.email/) | [GPL-3.0](https://github.com/mailcow/mailcow-dockerized/blob/master/LICENSE) | [2016](https://github.com/mailcow/mailcow-dockerized) | [2026-11, Nov 5, 2026](https://github.com/mailcow/mailcow-dockerized/releases/tag/2026-11) | PHP (Docker suite around Postfix and Dovecot) |
| [Mail-in-a-Box](https://mailinabox.email/) | [CC0](https://github.com/mail-in-a-box/mailinabox/blob/main/LICENSE) | [2014](https://github.com/mail-in-a-box/mailinabox/blob/main/CHANGELOG.md) | [v78, Oct 22, 2026](https://github.com/mail-in-a-box/mailinabox/blob/main/CHANGELOG.md) | Python / Shell (configures Postfix and Dovecot) |
| [Mailu](https://mailu.io/) | [MIT](https://github.com/Mailu/Mailu/blob/master/LICENSE.md) | [2016](https://mailu.io/2024.06/) | [2024.06.68, Nov 8, 2026](https://github.com/Mailu/Mailu/releases/tag/2024.06.68) | Python (Docker suite) |
| [Modoboa](https://modoboa.org/) | [ISC](https://github.com/modoboa/modoboa/blob/master/LICENSE) | [2010](https://modoboa.org/en/blog/release-081-out/) | [2.13.0, Nov 13, 2026](https://github.com/modoboa/modoboa/releases/tag/2.13.0) | Python (web UI around Postfix and Dovecot) |
| [Postfix](https://www.postfix.org/) | [EPL-2.0 / IBM Public License 1.0](https://github.com/vdukhovni/postfix/blob/master/postfix/LICENSE) | [1998](https://www.postfix.org/14blue.html) | [3.11.7, Sept 7, 2026](https://www.postfix.org/announcements.html) | C |
| [Stalwart](https://stalw.art/) | [AGPL-3.0 (Community); proprietary (Enterprise)](https://stalw.art/open-source/) | [2022](https://github.com/stalwartlabs/jmap-server/releases/tag/v0.1.0) (unified server 2023) | [v1.1.0, Nov 9, 2026](https://github.com/stalwartlabs/stalwart/releases/tag/v1.1.0) | Rust |
| [Mox](https://www.xmox.nl/) | [MIT](https://github.com/mjl-/mox/blob/main/LICENSE.MIT) | [2023](https://github.com/mjl-/mox/releases/tag/v0.0.2) | [v0.0.17, Aug 19, 2026](https://github.com/mjl-/mox/releases/tag/v0.0.17) (commits through Oct 27, 2026) | Go |
| **Commercial / proprietary on-premises** | | | | |
| [Axigen](https://www.axigen.com/) | proprietary | [2005](https://www.axigen.com/press/press-releases/axigen-launching_1.html) | [10.7.4, Nov 12, 2026](https://www.axigen.com/updates/axigen-10.7.4) | not published |
| [CommuniGate Pro](https://www.communigate.com/) | proprietary | [1998](https://lwn.net/1998/0903/a/stalker.html) | not published | not published |
| [Kerio Connect](https://gfi.ai/kerioconnect/) | proprietary | not published | [10.0.9p2, June 29, 2026](https://gfi.ai/resource/kerioconnect-product-releases/) | not published |
| [IceWarp](https://www.icewarp.com/) | proprietary | [2001](https://blog.icewarp.com/blog/article/nice-to-meet-you-were-icewarp) | [14.3.0.13, Oct 21, 2026](https://www.icewarp.com/downloads/download/) | not published |
| [MailEnable](https://www.mailenable.com/) | proprietary | not published | [10.62, Nov 3, 2026](https://mailenable.com/rss/html.asp) | not published |
| [MDaemon](https://mdaemon.com/pages/mdaemon-email-server) | proprietary | [1996](https://blog.mdaemon.com/email-50-the-first-killer-app) | [26.5.0, Oct 20, 2026](https://files.mdaemon.com/mdaemon/release/RelNotes_en.html) | not published |
| [Exchange Server](https://learn.microsoft.com/en-us/exchange/exchange-server?view=exchserver-se) | proprietary | [1996](https://news.microsoft.com/source/1996/04/02/microsoft-exchange-server-available/) | [SE RTM Nov26SU, Nov 10, 2026](https://learn.microsoft.com/en-us/exchange/new-features/build-numbers-and-release-dates) | not published |
| [SmarterMail](https://www.smartertools.com/smartermail/business-email-server) | proprietary | [2003](https://portal.smartertools.com/kb/a3758/key-feature-and-version-milestones-in-smartermail.aspx) | [Build 9807, Nov 7, 2026](https://www.smartertools.com/smartermail/release-notes/current/) | .NET |
| [Zimbra](https://www.zimbra.com/) | proprietary (licensed editions) | [2005](https://blog.zimbra.com/2005/08/setting-up-a-zimbra-development-environment/) | [Daffodil 10.1.21, Sept 24, 2026](https://wiki.zimbra.com/wiki/Zimbra_Releases/10.1.21) | Java |

**AI-written mail servers.** We looked for email servers written by AI agents in C or Go. We did not find a production-ready, from-scratch C or Go mail server that its authors present as fully LLM-generated. MailPace published a write-up of [vibe-coding an SMTP gateway in Rust](https://mailpace.com/blog/musings/vibe-coding-an-smtp-server) (not C or Go) with Claude Sonnet 4, with the prompts in the git history of [vibe-smtp](https://github.com/mailpace/vibe-smtp); that project is experimental and is not recommended for production. [Demir Mail Server](https://github.com/ibofe/email) is a GitHub Copilot-assisted installer and web UI around Postfix and Dovecot, not a new C or Go mail engine. Human-written Go mail servers already exist on this list (Mox and Maddy). Stalwart is written in Rust.

**SMTP history and standards**

SMTP was specified by Jonathan B. Postel in [RFC 821](https://www.rfc-editor.org/rfc/rfc821), Simple Mail Transfer Protocol, in August 1982, replacing his earlier [RFC 788](https://www.rfc-editor.org/rfc/rfc788) of November 1981. The same month, David H. Crocker's [RFC 822](https://www.rfc-editor.org/rfc/rfc822) defined the format of ARPA Internet text messages. In November 1995, [RFC 1869](https://www.rfc-editor.org/rfc/rfc1869) added SMTP Service Extensions (ESMTP) and the EHLO command that later extensions use. The protocol and the message format were revised in [RFC 2821](https://www.rfc-editor.org/rfc/rfc2821) and [RFC 2822](https://www.rfc-editor.org/rfc/rfc2822) (April 2001), then again in [RFC 5321](https://www.rfc-editor.org/rfc/rfc5321) and [RFC 5322](https://www.rfc-editor.org/rfc/rfc5322) (October 2008). Those 2008 documents remain the current SMTP and Internet Message Format specifications (Draft Standard).

Later additions include a STARTTLS extension for running SMTP over TLS ([RFC 3207](https://www.rfc-editor.org/rfc/rfc3207), February 2002), a separate message-submission service ([RFC 6409](https://www.rfc-editor.org/rfc/rfc6409), November 2011, Internet Standard), and SMTPUTF8 for internationalized email ([RFC 6531](https://www.rfc-editor.org/rfc/rfc6531), February 2012). Clients typically collect mail with POP3 ([RFC 1939](https://www.rfc-editor.org/rfc/rfc1939)) or IMAP (IMAP4rev1 in [RFC 3501](https://www.rfc-editor.org/rfc/rfc3501), replaced by IMAP4rev2 in [RFC 9051](https://www.rfc-editor.org/rfc/rfc9051)); JMAP ([RFC 8620](https://www.rfc-editor.org/rfc/rfc8620) and [RFC 8621](https://www.rfc-editor.org/rfc/rfc8621)) offers a newer JSON API. Domain authentication uses SPF ([RFC 7208](https://www.rfc-editor.org/rfc/rfc7208)), DKIM ([RFC 6376](https://www.rfc-editor.org/rfc/rfc6376)), and DMARC, which was first published as Informational [RFC 7489](https://www.rfc-editor.org/rfc/rfc7489) in March 2015 and was replaced in May 2026 by Proposed Standard [RFC 9989](https://www.rfc-editor.org/rfc/rfc9989) (from the DMARCbis work), together with [RFC 9990](https://www.rfc-editor.org/rfc/rfc9990) (aggregate reporting) and [RFC 9991](https://www.rfc-editor.org/rfc/rfc9991) (failure reporting). Related mechanisms include MTA-STS ([RFC 8461](https://www.rfc-editor.org/rfc/rfc8461)), SMTP TLS Reporting ([RFC 8460](https://www.rfc-editor.org/rfc/rfc8460)), DANE for SMTP ([RFC 7672](https://www.rfc-editor.org/rfc/rfc7672)), and the experimental ARC protocol ([RFC 8617](https://www.rfc-editor.org/rfc/rfc8617)). Citations were checked against the RFC Editor on Nov 13, 2026.

| RFC | Title | Date | Status |
| --- | --- | --- | --- |
| **Mail transfer and message format** | | | |
| [RFC 821](https://www.rfc-editor.org/rfc/rfc821) | Simple Mail Transfer Protocol | August 1982 | Obsoleted by RFC 2821 |
| [RFC 822](https://www.rfc-editor.org/rfc/rfc822) | Standard for the Format of ARPA Internet Text Messages | August 1982 | Obsoleted by RFC 2822 |
| [RFC 1869](https://www.rfc-editor.org/rfc/rfc1869) | SMTP Service Extensions (ESMTP) | November 1995 | Obsoleted by RFC 2821 |
| [RFC 2821](https://www.rfc-editor.org/rfc/rfc2821) | Simple Mail Transfer Protocol | April 2001 | Obsoleted by RFC 5321 |
| [RFC 2822](https://www.rfc-editor.org/rfc/rfc2822) | Internet Message Format | April 2001 | Obsoleted by RFC 5322 |
| [RFC 5321](https://www.rfc-editor.org/rfc/rfc5321) | Simple Mail Transfer Protocol | October 2008 | Draft Standard |
| [RFC 5322](https://www.rfc-editor.org/rfc/rfc5322) | Internet Message Format | October 2008 | Draft Standard |
| **Submission, TLS and internationalized email** | | | |
| [RFC 3207](https://www.rfc-editor.org/rfc/rfc3207) | SMTP Service Extension for Secure SMTP over Transport Layer Security (STARTTLS) | February 2002 | Proposed Standard |
| [RFC 6409](https://www.rfc-editor.org/rfc/rfc6409) | Message Submission for Mail | November 2011 | Internet Standard |
| [RFC 6531](https://www.rfc-editor.org/rfc/rfc6531) | SMTP Extension for Internationalized Email (SMTPUTF8) | February 2012 | Proposed Standard |
| **Mailbox access** | | | |
| [RFC 1939](https://www.rfc-editor.org/rfc/rfc1939) | Post Office Protocol - Version 3 | May 1996 | Internet Standard |
| [RFC 3501](https://www.rfc-editor.org/rfc/rfc3501) | Internet Message Access Protocol - Version 4rev1 | March 2003 | Obsoleted by RFC 9051 |
| [RFC 9051](https://www.rfc-editor.org/rfc/rfc9051) | Internet Message Access Protocol (IMAP) - Version 4rev2 | August 2021 | Proposed Standard |
| [RFC 8620](https://www.rfc-editor.org/rfc/rfc8620) | The JSON Meta Application Protocol (JMAP) | July 2019 | Proposed Standard |
| [RFC 8621](https://www.rfc-editor.org/rfc/rfc8621) | The JSON Meta Application Protocol (JMAP) for Mail | August 2019 | Proposed Standard |
| **Authentication and reporting** | | | |
| [RFC 7208](https://www.rfc-editor.org/rfc/rfc7208) | Sender Policy Framework (SPF) for Authorizing Use of Domains in Email, Version 1 | April 2014 | Proposed Standard |
| [RFC 6376](https://www.rfc-editor.org/rfc/rfc6376) | DomainKeys Identified Mail (DKIM) Signatures | September 2011 | Internet Standard |
| [RFC 7489](https://www.rfc-editor.org/rfc/rfc7489) | Domain-based Message Authentication, Reporting, and Conformance (DMARC) | March 2015 | Informational; obsoleted by RFC 9989, RFC 9990 and RFC 9991 |
| [RFC 9989](https://www.rfc-editor.org/rfc/rfc9989) | Domain-Based Message Authentication, Reporting, and Conformance (DMARC) | May 2026 | Proposed Standard |
| [RFC 9990](https://www.rfc-editor.org/rfc/rfc9990) | Domain-Based Message Authentication, Reporting, and Conformance (DMARC) Aggregate Reporting | May 2026 | Proposed Standard |
| [RFC 9991](https://www.rfc-editor.org/rfc/rfc9991) | Domain-Based Message Authentication, Reporting, and Conformance (DMARC) Failure Reporting | May 2026 | Proposed Standard |
| [RFC 8617](https://www.rfc-editor.org/rfc/rfc8617) | The Authenticated Received Chain (ARC) Protocol | July 2019 | Experimental |
| **SMTP transport security** | | | |
| [RFC 8461](https://www.rfc-editor.org/rfc/rfc8461) | SMTP MTA Strict Transport Security (MTA-STS) | September 2018 | Proposed Standard |
| [RFC 8460](https://www.rfc-editor.org/rfc/rfc8460) | SMTP TLS Reporting | September 2018 | Proposed Standard |
| [RFC 7672](https://www.rfc-editor.org/rfc/rfc7672) | SMTP Security via Opportunistic DNS-Based Authentication of Named Entities (DANE) Transport Layer Security (TLS) | October 2015 | Proposed Standard |

- **Open source**
- [docker-mailserver.github.io](https://docker-mailserver.github.io/docker-mailserver/latest/) - fullstack but simple mail server (SMTP, IMAP, LDAP, anti-spam, anti-virus) using Docker | X: none found
- [dovecot.org](https://dovecot.org/) - open-source IMAP and POP3 email server (Community Edition) | X: none found
- [hmailserver.com](https://www.hmailserver.com/) - free, open-source email server for Microsoft Windows | X: none found
- [iredmail.org](https://www.iredmail.org/) - free, open-source mail server solution for Linux and BSD | X: none found
- [maddy.email](https://maddy.email/) - composable all-in-one mail server | X: none found
- [mailcow.email](https://mailcow.email/) - mailcow: dockerized, a mail server suite that runs in Docker | [X: @mailcow_email](https://x.com/mailcow_email)
- [mailinabox.email](https://mailinabox.email/) - easy-to-deploy mail server in a box | X: none found
- [mailu.io](https://mailu.io/) - simple yet full-featured mail server as a set of Docker images | X: none found
- [modoboa.org](https://modoboa.org/) - open-source email server with a web user interface | X: none found
- [postfix.org](https://www.postfix.org/) - Wietse Venema's mail transfer agent (SMTP server) | X: none found
- [stalw.art](https://stalw.art/) - open-source mail and collaboration server with JMAP, IMAP4, POP3, SMTP, CalDAV, CardDAV and WebDAV | [X: @stalwartlabs](https://x.com/stalwartlabs)
- [xmox.nl](https://www.xmox.nl/) - Mox: modern, secure, all-in-one email server | X: none found
- **Commercial / proprietary on-premises**
- [axigen.com](https://www.axigen.com/) - mail server software for on-prem and cloud-native deployment | [X: @axigen](https://x.com/axigen)
- [communigate.com](https://www.communigate.com/) - CommuniGate Pro unified communications server | [X: @CommuniGate](https://x.com/CommuniGate)
- [gfi.ai](https://gfi.ai/kerioconnect/) - GFI KerioConnect: mail server with email, calendars, contacts and instant messaging for Windows, macOS and Linux, on-premises or hosted | X: none found
- [icewarp.com](https://www.icewarp.com/) - business email and collaboration suite; cloud, on-prem or hybrid | X: none found
- [mailenable.com](https://www.mailenable.com/) - Windows mail server software with webmail, CalDAV, CardDAV, antivirus and spam filtering | X: none found
- [mdaemon.com](https://mdaemon.com/pages/mdaemon-email-server) - MDaemon Email Server for Windows; a Microsoft Exchange alternative, on-premises or hosted | [X: @MDaemon_Email](https://x.com/MDaemon_Email)
- [microsoft.com](https://learn.microsoft.com/en-us/exchange/exchange-server?view=exchserver-se) - Exchange Server Subscription Edition (SE), the current on-premises Exchange Server | X: none found
- [smartertools.com](https://www.smartertools.com/smartermail/business-email-server) - SmarterMail, a business email and collaboration server for Windows and Linux | [X: @SmarterTools](https://x.com/SmarterTools)
- [zimbra.com](https://www.zimbra.com/) - email and collaboration software; Daffodil (v10) Professional and Standard editions require a license | X: none found

Number of links: 21