Web.de App does not open, what to do?

The Web.de app does not open on my laptop, which means I can't watch my emails. I was also in the browser and tried to log in, but I do not remember my password. What should I do?

Eifach try the app to reinstall. If it still does not work, try it on the phone. Because of the password just press "password forgotten". Or otherwise write to the support once over another mail or over the Internet.