The mail server is a software program that controls email transmission and reception over the internet using email protocols. Most people primarily use Gmail, Outlook, and ProtonMail, among other email providers. These services, however, frequently demand the use of their infrastructure services. Many consumers and businesses frequently business have their own mail servers so they may own, maintain, and control all of their data.

Solutions for email marketing can be built using self-hosted Open-source Mail servers. However, some email marketing programs feature built-in mail servers, while others function well with other mail programs. Choosing a free, open-source email server that will meet your needs can be overwhelming, given the wide variety available. These servers appear to be essential to your business’s operations because they save costs and improve security. To help you with this, here’s the list of compiled the most popular open-source mail servers for business and individual use:

1. iRedMail

The best option for converting your Linux-based server into a potent open-source email server is iRedMail. On all current Linux versions, it will operate without a glitch. The other mail systems are very dissimilar from iRedMail. As a result, users now see it as one of their favorite servers. The support for infinite accounts is another exciting feature. It is possible for you to set up as many mail accounts as you like. The server is, by default, secure. Both the passwords and every email are saved and encrypted.

  • Quarantining detected spam into SQL.
  • Database support OpenLDAP, MariaDB, MySQL, PostgreSQL.
  • Unlimited Accounts.
  • SpamAssassin, DKIM, ClamAV, SPF, greylisting, blacklisting.
  • Webmail.
  • Spam filtering.

2. hMailServer

The second open-source mail server that can be recommended is hMailServer. It is a fully functional email server with functional similarities to those in iRedMail. However, it only supports Windows Servers. hMailServer is compatible with widely used email protocols (IMAP, SMTP, and POP3). It provides spam protection using external anti-spam software like ASSP and SpamAssassin. hMailServer offers full support for webmail clients.

  • hMailServer has unique Antispam features. 
  • It supports SMTP and IMAP.
  • It has many features that help you to collaborate on different projects. 
  • You can sync it with webmail. 

3. Modoboa

Modoboa is an easy-to-install, free, open-source email server. It has the ability to build a fully functional email server that is comparable to commercial providers. It enables many domains in a single configuration, calendar, and contact book management. You can use a wide range of administration features, such as monitoring, real-time statistics, security settings, users, and permission manager. A webmail client and support for multiple languages are also included in this server.

  • Administration panel to manage domains, aliases, mailboxes, and more.
  • Autoreply messages for Postfix.
  • Webmail.
  • Built-in monitoring.
  • Per-user Sieve filters.

4. Dwarf Mail Server

The SMTP, POP3, and IMAP4rev1 protocols were supported by the Java-based Dwarf Mail Server. By using pluggable Mail filters and agents, it can process rich app application message processing as well as virtual domains. This server is easy to use, and it helps to handle large clients. You can use the wide range of features and functions that come along with this domain.

  • The application logic layer is provided by agents and Mail filters.
  • Virtual mail hosts in POP3/SMTP/ IMAP4 server.
  • It can handle multiple domains.
  • Application-independent authorization and authentication.

5. Zimbra

The server provides a wide range of services, including task management, document management, calendar management, and extensive search options. You can securely share documents, calendars, and address books. It can be used to manage databases, emails that are sent and received, and much more. By incorporating all the main operating systems, it provides complete cross-platform support as well. Anti-spam and antivirus features are fully integrated into the server.

  • IMAP and POP Email support.
  • Mobile Web Client.
  • Command Line Interface (CLI).
  • CalDAV Calendar & CardDAV Contacts.
  • Web Administration Console.


James email server, also known as the Java Apache Mail Enterprise Server, consists of a wide range of parts. They all work together to produce an effective, reliable, seamless, secure, and expandable set of mail servers. You can design your own unique response for each individual email using the Inversion of Mail Control Platform. Along with that, the James Mailet Container also enables you to modify the filtering and routing rules. As the Java Apache Mail Enterprise Server is an open-source project, all technical developments are exclusively based on technical standards.

  • POP3, SMTP, IMAP, LMTP, JMAP and ManageSieve.
  • Independent, pluggable and extensible email processing agents.
  • Storage API: Mailbox API / User API / Search API.
  • Storage Implementations: Cassandra / HSQLDB / PostgreSQL / ElasticSearch / MySQL.

7. Mail-in-a-Box

You have complete control over your emails when using the Mail-in-a-Box email server. The platform turns a cloud computer into a usable mail server. The setup of this requires little technical expertise. With the help of a desktop application or a mobile device, users of this platform can access webmail and an IMAP/SMTP server. All the typical email functions are available here, such as auto-configuration, backups that are automatically performed and spam filtering. Along with them, you can also sync your contacts and calendars with it.

  • You can add multiple accounts.
  • You can monitor and add aliases with its control panel feature.
  • It has a spam filtering feature.
  • It has a flexible API. This will allows you to integrate with other applications. 

8. Citadel

Citadel is an AJAX-powered groupware platform, and it is a 100% open-source server. Along with IMAP, SMTP, POP3, and GroupDAV its access to its content, it offers a “Web 2.0” interface. IMAP, SMTP, POP3, XMPP, ManageSieve, and Citadel are the server protocols that it implements for the smooth functioning of the server. It is developed to be user-friendly in approach.

  • Groupware- address book, file storage, and notes.
  • Group scheduling and calendaring.
  • Multiple domain support.
  • Integrated server-side mail filtering and sorting.

9. MailEnable

There are free and paid versions of the MailEnable server. If you need a reliable SMTP, POP3 webmail service, MailEnable will satisfy your needs. The installation process is simple, and strong administration software supports it. Despite being an open-source server that is available for free, it is free from malware and adware. As you may anticipate, the free edition offers fewer features than the premium version. But the fundamental components are enough for most organizational requirements. 

  • AJAX webmail client.
  • Manage all your contacts in the web browser.
  • Webmail Calendar.
  • Appointment invitations & Scheduling.

10. Zentyal

Zentyal Server is a complete network management solution that is more than just a mail server. It is available in two versions, community and commercial (also called the development version). It is made to accommodate the demands of small and medium-sized businesses. Zentyal Server included a Directory & Domain server with native active directory compatibility and a Mail Server with ActiveSync and webmail. It also has a Gateway with a firewall and a proxy, a DNS/DHCP server, and a Virtual Private Network.

  • Support File sharing.
  • Mail Server with webmail and ActiveSync.
  • Supported protocols: SMTP, IMAP, POP3, CardDAV, CalDAV, SIEVE.

11. Docker Mailserver

Docker mailserver is used by many business owners to strengthen client-business ties. The tools and protocols included with Docker mailserver make emailing simple and quick. With this, you will have access to a lot of capabilities. Docker-mailserver gives business owners server-side access so they may fully control email. You may deliver, store, accept, and forward messages using the Docker mailserver. To make it simple for you to do more than send and receive emails, this server will perform several jobs in the interim.

  • It has POP3, SMTP, and IMAP functionalities.
  • It has an intuitive webmail interface. 
  • It has TLS encryption.

12. Mailu

You can choose Mailu if you want an email server with lots of features. By offering users a server that is simple to set up and manage, this free software benefits users lots of users. IMAP, SMTP, IMAP+, and Submission are just a few examples of common email servers and protocols that you can utilize. It also has capabilities like numerous webmail, personalized routing, domain aliases, and administrative interfaces in addition to online access. An easy way for users to save time and effort is to use aliases, auto-forward, autoreply, and fetched accounts. 

  • You can domain aliases, create aliases, and custom routing.
  • It has an administration interface that will help to handle multiple webmails. 
  • Users get auto-forward, autoreply, and fetched accounts features.

Bottom Line

You can make use of any of the email servers listed here for both business and individual purposes. Most of this software is easy to use without any complex functionality. Carefully go through all 12 software and choose the one which suits you or your business.