Install clawsker by entering the following commands in the terminal:
sudo apt update sudo apt install clawsker
Description:
Configuration tweaker for Claws Mail
Clawsker is an applet to edit the so called Claws Mail hidden preferences. . Claws Mail is a fast, lightweight and feature-rich MUA with a high number of configurable options. To keep the binary small and fast some of these preferences which not widely used are not provided with a graphical interface for inspection and/or modification. . Users wanting to edit such preferences had to face raw edition of their configuration files, now you can do it with a convenient GTK+2 interface using Clawsker.
Homepage: http://www.claws-mail.org/clawsker.php
Version: 1.1.1-1
Section: universe/mail