It is convenient to use email services such as Gmail, Proton Mail, and Outlook to send and receive emails, no matter what email client you are using.
And for all that, you use their mail servers for email transactions. Therefore, the security, reliability, and privacy of your emails depends on someone else’s.
But what if you want to own your email infrastructure and control the data? You need an open source email server, which should solve your problem.
If you’re still curious, the email server allows you to:
- Build your own mail back-to-store email accounts
- Control security and reliability with self-hosting
- Host on your preferred server architecture
- It gives you the ability to create unlimited accounts
Of course, this is not for end users. System administrators in small to medium businesses, self-hosters will find these programs interesting.
Given that you now have an idea of ββthe benefits of an open source email server, here are some of the best options you can find:
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The list includes mail servers and some solutions that make it possible to create/create an email server. Some may offer managed services and others may be self-hosted.
1. Mail
postal It is a feature-rich mail server that can be used by websites and servers. that it Designed specifically for outgoing emails With no mailbox management features.
the documentation It helps to start with all the basics. You can use docker and configure mail on your server.
With Postal, you can create mail servers/users for multiple organizations, access the outgoing/incoming message queue, real-time delivery information, and built-in features to ensure emails are delivered.
the main points:
- Real time delivery information
- Click and open tracking
- Designed for outgoing emails
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Maintaining and configuring an email server is not an easy task. You should only proceed with mail server setup if you know all it takes to reliably send/receive emails.
2. mailcow

mailcow It is a mail server suite that contains tools that help you create a web server, manage your mailbox, and more.
If you’re not looking to send transactional emails, mailcow has your back. You can consider it as a group program.
Like other mail servers, it works with Docker, where each container represents an application, and they are all connected.
mailcow’s web interface lets you do everything from one place. You can explore more about the project on its website GitHub page or documentation.
the main points:
- Easy to manage and update
- Affordable paid support
- It can pair with other mail servers if needed
Suggest reading π
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3. Cuttlefish

Do you want a simple transactional email server? squid It is an open source mail server that is incredibly easy to use.
You get a simple web user interface to check stats and monitor outgoing emails.
Compared to some full-fledged email services like Sendgird or Mailgun, Cuttlefish doesn’t offer all kinds of features, Considering it is in beta on time. You can only choose it if you need something very simple and want to work reliably.
Find out more about it on their site GitHub page.
the main points
- Simple transactional email server
- easy to use
4. Apache James

mosques is an abbreviation for Java Apache Mail Enterprise Server.
As the name suggests, it is an open source, enterprise-focused mail server built with Java. You can use the email server as an SMTP relay or an IMAP server, depending on the requirements.
Compared to others, James may not be the easiest to configure or install. However, you can look at the documentation or GitHub page To judge for yourself.
the main points:
- Easy management after setup
- Trusted and used by open source organizations
- distributed server
5. Movement
a movement It is a modern, open source SMTP server built with Node.js. If you can create it for your business/website, you don’t need to look any further SMTP Services.
The mail server is designed to provide the best performance. One of the most notable features of Haraka is that it features a plug-in system that allows programmers to change server behavior to the maximum extent.
Think of it as a premium and scalable outgoing mail delivery server. Some popular names like Craigslist and DuckDuckGo Email Protection take advantage of Haraka.
Find out more about it on their site GitHub page.
the main points:
- Created with Node.js
- Plugin system to expand functionality
6. Modobwa

Modobwa It is an all-in-one open source solution.
It can help you build a mail server and give you the ability to manage your emails. You can create calendars, add unlimited domains, create filtering rules, and access webmail. Modoboa also offers paid maintenance options if you want their professional help in setting it up and managing it.
Not just an all-in-one solution, but it provides a quick way to start your email infrastructure.
the main points:
- All-in-one option
- Paid assistance available
- Built-in monitoring
7. Postfix
Postfix is ββa mail transport agent. It may not be a server on its own, but it pairs with some other solutions that help you create an email server.
while mailcow postfix (and you can configure it with similar solutions), you can choose to use it separately depending on your use case. Postfix is ββalso the default mail transfer agent in Ubuntu server.
Postfix can be used as an external SMTP protocol. Don’t forget, you can also set up Postfix to Work with Gmail. It’s easy to configure, and the documentation provided for it is very helpful.
the main points:
- Easy to configure
- flexible
Suggest reading π
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8. Madi
material It is a great option if you need a lightweight mail server application. The official description says that “Buildable all-in-one mail server“.
When you compare Maddy to mailcow, you will find that it offers some of the features that you get with mailcow, which means that it is not just limited to outgoing emails like the others.
Maddy is known for its use case, where it can replace multiple options like Postfix with a single application. You can send/receive and store messages with Maddy via SMTP and IMAP. The storage feature is in beta at the time of writing the article.
the main points:
- Lightweight
- It replaces the multiple use cases you get with options like Postfix
- Don’t rely on Docker
9. The dove
pigeon It is an open source IMAP server that acts as a proxy for mail delivery. It can work with Postfix because they both do different things.
Compared to other solutions, it offers easy management, reliable emailing capabilities, and self-healing powers.
Dovecot offers an outstanding offering for large infrastructure with professional support.
the main points:
- Easy management
- Self-healing capabilities
- Performance focused
10. Poste.io

Poste.io It uses mail server solutions such as Haraku and Dovecot and other open source components. From spam filters to an antivirus engine.
If you want to set up an open source mail server with some of these components and be able to easily manage and secure things, Poste.io is an excellent choice.
the main points:
- Easy to manage and build with multiple open source mail server components
- Administration panel interface
11. iRedMail.com
e-mail It is similar to mailcow which helps you to build a mail server using different open source components. You can also manage your calendars using the created mail server.
While you can set it up yourself, it does provide paid professional support if you need it.
You get a web panel, support for a Linux distro to host, and the ability to create unlimited accounts.
the main points:
- easy to use
- Web panel for easy management
12. Mailu

Milo It is a Docker-based mail server that gives you the best of everything while limiting some features.
This does not mean that it is bad. Mailu aims to focus on essential features without adding many capabilities that are not useful to most people. Even with that goal, it stands out by adding ARM support, Kubernetes support, and other things.
You get a standard mail server, advanced email features, a web admin interface, and privacy-focused features.
the main points:
- Simple interface
- A concentrated solution without bells and whistles
- ARM support
Ready to build and manage your email server?
With open source tools and email servers, you can control your data and manage/optimize email transactions for your business or website.
As I mentioned, it takes a lot of work to do this. So, open source, self-hosted email servers can work if you want to have a customized experience and have a team that can be responsible for it.
π¬ I’m sure there are many options, like mail in a boxto help you quickly deploy the mail server.
Here, we have tried to select the best ones for your convenience. What is your favorite open source email server?