Open-source with high security standards: The software Kolab is free and, if you have enough technical know-how, can be adapted to your specific needs. It was originally developed for the German Federal Office for Information Security, so it will come as no surprise that this Microsoft Exchange alternative places a premium on safety and data protection.
Anti-spam and anti-virus solutions are also included in the software. As with many of its other features, Kolab uses well-established open-source modules for these solutions, which are also implemented in other projects. Connections with other collaboration solutions such as OwnCloud also set Kolab apart.
Since Kolab is open-source, it can easily be installed in Linux. However, if you don’t want to install and configure this groupware solution on your own, it’s also possible to take advantage of the services of the company Kolab Enterprise. Then you’ll be able to access all its features in a hosted cloud.