Install libpfqueue0 by entering the following commands in the terminal:
sudo apt update sudo apt install libpfqueue0
Description:
interactive console-based tool to control MTA queues (library)
pfqueue is a queue manager for different MTAs (currently postfix and exim), allowing to delete, hold, release, or requeue messages. . This package contains the libraries.
Homepage: http://pfqueue.sourceforge.net/
Version: 0.5.6-9build2
Section: universe/libs