On Thu, 5 Dec 2019 11:42:43 +0100 ratatouille <ratatouille at bitclusive.de> wrote: > I am using Linux Mint 19.1 Cinnamon. Apparently Linux Mint 19.1 is based on Ubuntu bionic (18.04 LTS). If that is correct then you need the package called claws-mail-managesieve. https://packages.ubuntu.com/bionic/claws-mail-managesieve with regards Paul