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Microsoft Exchange: What alternatives are there?


With Microsoft Exchange Server, companies can manage all their emails, appointments and documents centrally so that a large group of employees can access them and even work on them simultaneously. In a working world that increasingly relies on mobility and flexibility, this enables simple and time-saving collaboration.

The software is specially tailored to the Windows infrastructure, especially for use with Outlook, and is, therefore, one of the most widely used exchange server solutions. But this does not mean that there is no alternative to Exchange. Depending on the structure and flexibility of your IT infrastructure, the products of other providers may well be more suitable for you. Before you decide on an exchange server alternative, however, you should take a close look at the advantages and disadvantages of the various software solutions.


  • The advantages and disadvantages of Microsoft Exchange

  • Exchange server alternatives at a glance

  • All Exchange server alternatives at a glance


Microsoft Exchange Server offers many advantages, especially for small and medium-sized enterprises, as the servers can be rented externally and therefore no cost-intensive in-house administration of the IT infrastructure is necessary. In contrast, with a so-called on-premises solution (i.e. the servers are housed directly at one's own location), one retains full control over the data, but must also take care of the administration of the servers (incl. cumulative updates, data maintenance, etc.). This is often not feasible for smaller companies.

Due to the widespread use of Microsoft products, dealing with them is usually very uncomplicated for employees: Outlook is probably the best-known email client in the world. But not every administrator finds its management optimal. That is why IT experts often look for an alternative to Exchange. One of the main reasons for this is that the Microsoft product entails licensing costs. However, smaller organisations in particular prefer free versions of the mail server.


Exchange is so popular for good reason. The software offers many useful features and comprehensive administration options. But for some users and administrators, the software is still not the right choice. For example, many users want an Exchange alternative that is open source. Others are simply looking for more suitable functions.

Google Workspace

Google also offers an alternative to Exchange. In Google Workspace, you can find all the tools you could possibly need for your daily office work. Many users are already familiar with Gmail and Google Docs from their private lives. Google Hangouts are also included in the product range and give teams further possibilities for communication. With the paid Google Workspace, you bring the extensive functions to a professional level. Then, for example, you can also use your own email domain. In addition, administrators have several management options available in the professional version: Distribute rights, compile groups and enter security restrictions.

The Google Workspace is designed for working in Google's cloud. The advantage of this is that everything is set up perfectly and employees can work from any location while accessing all data. However, it is not possible to run the programmes via your own server.


  • Very extensive portfolio

  • Partly mobile and desktop app


  • Only available as SaaS

  • Not open source


Open source with high-security standards: The Kolab software is freely available to everyone and can also be adapted to your own requirements with sufficient expertise. The system originated at the German Federal Office for Information Security (BSI). The office commissioned this software, so it is not surprising that this Exchange alternative pays great attention to security and data protection.

Spam and virus protection is activated in the software by default. Here - as with many other functions - Kolab relies on open-source modules that have already been tested many times and are also used in other projects. The many connections to other collaboration solutions such as OwnCloud are interesting.

Since Kolab is open source, you can simply install the groupware software on a Linux system. However, it is also possible to use the services of Kolab Enterprise. In this case, all functions are already available to you in a hosted cloud. You do not have to install and configure the groupware solution yourself.


  • Open source

  • Interfaces to other tools

  • High-security standards


Zimbra is also open source and can be used freely by anyone. You then get a strong email service that the whole company can use to manage communication. Users can access their email inbox via the browser. Zimbra offers all the functions needed to manage emails, calendars, contacts and notes. In addition to the free version, a paid version is also available to users. With this version, connections (via MAPI) to email clients such as Outlook are possible.

The open-source version already includes support for ActiveSync. This technology from Microsoft enables data to be synchronised across several devices. The software can be installed on various Linux distributions.


  • Open source

  • Extensive web application


  • Link to Outlook only in the paid version

Kerio Connect

Kerio Technologies develops software solutions for companies. The company's Exchange alternative is called Connect. This is a mail server that practically runs under Linux, Windows and also macOS. The manufacturer of the software also promotes the product with its easy set-up: within only 20 minutes it should be possible for employees to work together in the Exchange alternative. Kerio Connect can be managed either via the local data centre or via a cloud.

A special feature of the software is its own instant messaging service. This allows employees of the organisation to quickly exchange information with each other without having to write a complete email. Since the service runs via XMPP, software from other manufacturers can also be used for the chat function. This also applies to the mail service: people can access their emails with different clients or use Kerio's web application. In addition, Kerio Connect - like other alternatives - relies on Microsoft ActiveSync to distribute messages to mobile devices.


  • Easy to set up

  • Cross-platform

  • Inexpensive

  • Interfaces for third-party software


  • Not open source

CommuniGate Pro

Another powerful alternative to Exchange: CommuniGate Pro provides all the functions you need for communication within a company. In addition to the mail service, you can also share notes, calendars and tasks with your colleagues. To access the functions of the server, various client programmes such as Outlook, Thunderbird or Mail from Apple can be used. In addition, CommuniGate Pro also offers its own web application, which can be easily accessed via the browser and offers various layouts.

In addition, companies can also use CommuniGate Pro to implement VoIP and instant messaging. The software is available free of charge for small organisations. Those who want to use the Exchange alternative with more than five employees must purchase a licence.


  • Cross-platform

  • Extensive web application


  • Only free of charge to a small extent

  • Not open source


Regardless of whether you are looking for an Exchange alternative that is free and open source, or whether you want to order all the hardware at the same time: At least one of the products presented certainly offers the right solution.


Tip: You don't need a complete mail server for you and your team, but you still want to work together in one software? With collaboration tools, you can boost productivity and exchange among employees.



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