Install kopano-spooler by entering the following commands in the terminal:
sudo apt update sudo apt install kopano-spooler
Description:
Complete and feature rich groupware solution - email spooler
The Kopano Collaboration Platform (KCP) is a complete, stable and flexible groupware solution supporting open source as well as proprietary clients including mobile ones. It also features a web interface. . This package contains the email spooler that forwards emails from the Kopano server to an SMTP server.
Homepage: https://download.kopano.io/community/
Version: 8.5.5-0ubuntu1
Section: universe/mail