Open source shows the way out of dependency of MicrosoftDelft, )
A group of European journalists have diagnosed Europe’s administrators and governments a “fatal dependency of Microsoft ”. Their research shows with the example of Microsoft Office a chain of dependencies of only this single company. It also describes how some administrations could already break free from this dependency by using LibreOffice.
An important part of Microsoft Office is Outlook. But especially in Outlook the dependencies of Microsoft-solutions are larger than ever, as soon as you want to work in teams with emails and calendar. 
Web-based apps – the trend towards independency
Companies & users try to get away from the dependency where a central product like Outlook with services of only one vendor – which is the Microsoft Exchange Server or MSOffice365 ..
This only works by exchanging Outlook with another more open program. Here web based apps are a popular possibility. Concerning smartphones you can´t do without them. And producers of software prefer more and more to integrate their own app as a widget in web bases apps, too – instead of developing plugins for specific programs and to maintain them. This minimizes dependencies and simplifies the integration into a variety of programs from which not only the vendor, but the users benefit.
Kopano offers this feature
Kopano, a fork of Zarafa, offers with the Kopano DeskApp a platform, where users can communicate, organize themselves and share content. This web based app enables other providers to integrate in different ways, e.g. via widgets. The Kopano DeskApp is available for Windows, macOS and Linux. Most content and integrations are also available in the almost identical Kopano WebApp in internet browsers. But smartphones, tablets and Outlook (version 2013 and higher) are linked via Z-Push, the open-source-implement of the Exchange Active Sync Protocols (EAS). KOE moreover provides some group functions in Outlook.
Solutions like Kopano in combination with LibreOffice help users to disengage themselves of the dependency from Microsoft and enables companies to choose their software stack more freely. With more than 10 years of experienced in groupware Kopano refers to the users demands.
Companies that aim at low dependencies and want to keep control overr their software and data can use the open source code of the open source product and test it. They don´t have to trust in statement and promises of third parties.