In order to guarantee the best user experience, please use a recent web browser and allow JavaScript and Cookies on our page.
Please make sure to regularly update your browser, as this enables you to use the latest encryption methods.

Our recommendations for Linux, Mac, iOS, Windows:

Additionally the following web browsers work:

  • Google Chrome
  • Microsoft Edge

Minimum screen resolution for desktop devices is 1024x768 pixels.

Our recommendation for Android:

Please be advised that the mobile version of the office does not offer all available functionalities. Hence, we recommend the usage of e-mail clients on android devices.
Our recommendation:

  • OX Mail App - this is the app of our partner Open-Xchange. We also use their software for the mail back end. OX Mail App software is closed source.
  • K-9 as a FLOSS alternative

FairEmail or others might work.

We officially only support OX Mail App

If you need to change settings while you're underway, we recommend:

  • Google Chrome

The German internet security expert Mike Kuketz has more advice on Android Apps: Browsers and E-Mail Client (in German).

Many of our experienced users follow those recommendations - however, we do not provide support for these apps.