Alternatives to Mailcow
Dockerized open-source mail server suite with web admin and webmail. The listings below can replace it for an important use case. Each note says what changes if you switch.
The original
Mailcow
Dockerized open-source mail server suite with web admin and webmail.
Replacements
Listings that take over the same core job as Mailcow.
Mail-in-a-Box
Turnkey open-source script that builds a full mail server on Ubuntu.
Mail-in-a-Box sets up a full mail server with a turnkey script on a single Ubuntu machine without Docker, but it is tied to Ubuntu.
Poste.io
All-in-one Docker mail server with web admin and built-in TLS.
Poste.io runs in one Docker container with web admin, webmail and TLS included, but it is not open source and its free tier is limited.
iRedMail
Free open-source mail server installer for Linux and BSD.
iRedMail installs a full mail stack with one text-based script on many Linux and BSD distributions, without the Docker packaging Mailcow uses.
Modoboa
Open-source mail hosting platform with an admin UI and webmail.
Modoboa is an open-source self-hosted platform with an admin UI and webmail, with a smaller community than some larger self-hosted mail projects.
Stalwart
Rust-based all-in-one mail server supporting JMAP, IMAP, and SMTP.
Stalwart is a Rust all-in-one mail server supporting JMAP, IMAP and SMTP, from a newer project with a smaller ecosystem than established stacks.
Maddy
Composable single-binary open-source mail server written in Go.
Maddy is a single Go binary with lower complexity than a Docker suite, but has no bundled webmail listed and fewer guides available.
Similar software
Related functionality, not a direct replacement.
Proxmox Mail Gateway
Mail security gateway that filters spam and viruses in front of a mail server.
Maileroo Mail Tester
A free web tool that grades a test email for authentication, spam score, DNS and blacklists.
imapsync
Command-line tool for migrating or backing up between IMAP servers.
