Maddy Mail Server review 2026: a free, open-source, all-in-one Go mail server. Features, setup, licensing, pros and cons, and self-hosted alternatives.
Category
Developer Tools
Pricing
Open Source, from Free
Verified
Not yet
Last updated
July 18, 2026
Founded
2019
Open SourceSelf-Hosted
Overview
Maddy Mail Server is a free, open-source, self-hosted mail server written in Go that consolidates the many components of a traditional email stack, an MTA, an MX server, an IMAP server, and separate DKIM, SPF, DMARC, DANE, and MTA-STS services, into one binary with a single configuration file. It was created by developer Max Mazurov (foxcpp), with the project dating from around 2019, and is maintained on GitHub with dozens of community contributors.
Maddy is aimed at technically capable self-hosters and small organizations who want to run their own email infrastructure without separately installing and configuring Postfix, Dovecot, OpenDKIM, OpenSPF, and OpenDMARC, trading some of the flexibility of those mature, individually specialized daemons for a simpler, unified setup.
Key Features
Maddy can send mail as an MTA, receive mail as an MX server, and store and serve mailboxes over IMAP, all from a single daemon. It natively implements the modern email authentication and security stack, DKIM, SPF, DMARC, DANE, and MTA-STS, that major providers increasingly require to keep outbound mail out of spam folders.
The server supports flexible storage backends including local filesystem and Amazon S3-compatible blob storage, multiple authentication methods including PAM, system commands, and LDAP, and official Docker images for containerized deployment.
Pricing
Maddy Mail Server is completely free and open source, with no paid tiers, licenses, or subscriptions. It is licensed under the GNU General Public License version 3, having switched from the original MIT license starting with version 0.3.3/0.4.
Because it is self-hosted, the only real costs are the server or cloud instance running it; there is no vendor to pay and no usage-based fees.
Key Features
All-in-one mail daemon — Combines MTA, MX, and IMAP functionality into a single Go binary instead of requiring separate Postfix and Dovecot installations.
Built-in email authentication — Natively implements DKIM, SPF, DMARC, DANE, and MTA-STS to keep outbound mail authenticated and out of spam filters.
Unified configuration — A single configuration file controls SMTP, IMAP, filtering, authentication, and local delivery rules.
Flexible storage backends — Supports local filesystem storage as well as Amazon S3-compatible blob storage for mailboxes.
Multiple authentication methods — Integrates with PAM, system commands, or LDAP for user authentication.
Docker support — Ships official Docker images for straightforward containerized deployment.
SMTP/LMTP forwarding — Supports remote MX delivery and forwarding to downstream mail systems.
Lightweight Go codebase — Written entirely in Go, making it lightweight, fast, and relatively easy to audit compared to older C-based mail daemons.
Pros & Cons
Pros
Free and open source with no licensing costs.
Replaces a stack of separate daemons, including Postfix, Dovecot, OpenDKIM, OpenSPF, and OpenDMARC, with one binary and one config file.
Modern Go codebase that is easier to audit and deploy than legacy C-based mail servers.
Native support for the full modern email security stack, including DANE and MTA-STS.
Official Docker images simplify self-hosted deployment.
Cons
GPLv3 license requires derivative distributed works to also be open source, which can be a constraint for commercial products.
Smaller community and ecosystem than long-established projects like Postfix and Dovecot.
Fewer turnkey management interfaces or admin panels compared to bundled solutions like Mailcow.
Running any self-hosted mail server, including Maddy, requires ongoing sysadmin effort for deliverability and security.
As a newer project, it has a smaller track record in large-scale production deployments compared to decades-old mail server software.
Pricing
Open Source Free N/A
Frequently Asked Questions
Is Maddy Mail Server free?
Yes, Maddy is completely free and open source, licensed under the GNU General Public License version 3.
What does Maddy replace?
Maddy is designed to replace the combination of Postfix, Dovecot, OpenDKIM, OpenSPF, and OpenDMARC with a single unified mail server daemon.
What language is Maddy written in?
Maddy is written entirely in the Go programming language.
Does Maddy support DKIM, SPF, and DMARC?
Yes, Maddy natively implements DKIM, SPF, DMARC, DANE, and MTA-STS for modern email authentication and security.
Who created Maddy Mail Server?
Maddy was created by developer Max Mazurov, known online as foxcpp, and is maintained as an open-source project on GitHub.
Can Maddy run in Docker?
Yes, Maddy provides official Docker images for containerized deployment.