docker-mailserver vs Postal
Which should you use? A side-by-side look at what each one does, who it suits, what it costs, how hard it is to set up, and where each falls short.
Open source · MIT
A self-hosted email server packaged as a Docker container, with SMTP, IMAP and anti-spam built in.
Open source · MIT
Self-hosted mail server for sending and receiving email from your own websites and apps.
The short answer
Choose docker-mailserver if you need…
- People who want to run their own mail server on a machine they control
- Admins who already use Docker and want mail in a container
- Teams that want anti-spam, anti-virus and DKIM/DMARC handled in one package
- Users who prefer file-based configuration over a SQL database
Choose Postal if you need…
- Teams that want to run their own transactional email sending infrastructure
- Developers who need to send email from a web application and prefer self-hosting
- Organisations that want to keep mail data on servers they control
- Ruby developers who want to read or modify the mail server code
Side-by-side
| docker-mailserver | Postal | |
|---|---|---|
| Type | App | App |
| Price | Free and open source | Free and open source |
| Licence | MIT | MIT |
| GitHub stars | 19.7k | 16.9k |
| Setup difficulty | Advanced | Advanced |
| How you get it | Run with Docker | Clone and build from source |
| Main language | Shell | Ruby |
| Last code update | 6 days ago | 7 days ago |
What each one is
docker-mailserver
docker-mailserver is a full email server that runs inside a Docker container. It bundles common mail components such as Postfix for sending and receiving, Dovecot for IMAP and POP3 access, and several spam and virus filters. It is configured through files rather than a database, which the project describes as keeping setup simple and versioned.
Postal
Postal is an open source mail server that you run on your own machines. It is meant for websites and web servers that need to send and receive email, and the README positions it as a self-hosted alternative to hosted services such as Sendgrid, Mailgun or Postmark. The README excerpt provided does not detail its internal feature set, so the full capabilities come from the linked documentation.
Best for
docker-mailserver
- People who want to run their own mail server on a machine they control
- Admins who already use Docker and want mail in a container
- Teams that want anti-spam, anti-virus and DKIM/DMARC handled in one package
- Users who prefer file-based configuration over a SQL database
Postal
- Teams that want to run their own transactional email sending infrastructure
- Developers who need to send email from a web application and prefer self-hosting
- Organisations that want to keep mail data on servers they control
- Ruby developers who want to read or modify the mail server code
Strengths
docker-mailserver
- Bundles many mail components into one container, so there is less to wire together by hand
- Configuration is kept in files, with no SQL database to maintain
- Large community interest, with about 19,700 GitHub stars and an MIT license
Postal
- Open source under the MIT license, so the code can be inspected and modified
- Positioned as a full mail server covering both incoming and outgoing mail
- Active project with a large community, roughly 16,900 stars, and recent activity
Not ideal for
docker-mailserver
- Anyone who wants email hosting without running servers, since the README assumes you operate the server yourself
- Beginners with no experience of DNS, TLS certificates or mail deliverability, because setup involves those topics and the README points to documentation for initial setup
- People needing a managed or hosted service with support contracts, since the README says the issue tracker is not for personal support
Postal
- People who just need to send a few emails and want no server to manage, since a hosted service is simpler
- Anyone without server administration experience, because running a mail server involves DNS, IP reputation and security setup
- Users who need a turnkey desktop email client rather than server software
Trade-offs
docker-mailserver
- Running a mail server is demanding; the README points to documentation for initial setup and expects you to match docs to your image version
- Support is limited to the issue tracker and documentation, which the README says is not for personal support
- The project is maintained by volunteers since 2021, so response times are not guaranteed
Postal
- Operating a mail server is complex, and deliverability depends on your own DNS and IP setup
- The README excerpt gives little detail on requirements, so you must read the installation docs closely
- Self-hosting shifts maintenance, security and uptime responsibility to you
Getting started
docker-mailserver
Get started on the docker-mailserver websiteStep-by-step guide: how to use docker-mailserverPostal
Clone the repository
git clone https://github.com/postalserver/postalFrequently asked questions
What is the difference between docker-mailserver and Postal?
docker-mailserver: A self-hosted email server packaged as a Docker container, with SMTP, IMAP and anti-spam built in. Postal: Self-hosted mail server for sending and receiving email from your own websites and apps. docker-mailserver suits people who want to run their own mail server on a machine they control, while Postal suits teams that want to run their own transactional email sending infrastructure.
Are docker-mailserver and Postal free?
docker-mailserver: Free and open source. Postal: Free and open source.
Is docker-mailserver or Postal more popular?
docker-mailserver has more GitHub stars (19.7k) than Postal (16.9k). Popularity isn't the same as fit — check which one matches your use case above.
What are other alternatives to docker-mailserver and Postal?
Other options people compare them with include Cloud Mail.
Keep comparing
Built from our catalogue entries for both products: open-source details come from each project's README (AI-assisted, refreshed weekly) and GitHub data; AI-tool details are editorial. Spotted something wrong? Let us know from either product's page.