Install citadel-client by entering the following commands in the terminal:
sudo apt update sudo apt install citadel-client
Description:
complete and feature-rich groupware server (command line client)
This is package contains the command line client for Citadel, a complete and feature-rich open source groupware platform. . See the 'citadel-server' package for more information.
Homepage: http://www.citadel.org/
Version: 916-1
Section: universe/mail