Obviously I could fix the problem by installing the package gir1.2-ayatanaappindicator3-0.1. And it also works when installing gir1.2-appindicator3-0.1. Should be installed automatically with ayatana-webmail, shouldn't it?
Obviously I could fix the problem by installing the package gir1.2- ayatanaappindic ator3-0. 1. And it also works when installing gir1.2- appindicator3- 0.1. Should be installed automatically with ayatana-webmail, shouldn't it?