Install biff by entering the following commands in the terminal:
sudo apt update sudo apt install biff
a mail notification tool
biff is a small program that prints a message to your terminal when new email arrives. Actually, the message is printed by the comsat daemon, and biff just enables/disables the u+x permission flag for the terminal, which comsat uses to determine whether or not to write to your terminal. . biff is mainly of historic interest, since there are much better alternatives (such as xlbiff and gbuffy) that are network-aware and do not require a daemon. Although there are no known security problems, running additional services is often considered risky. . By default, the biff service is disabled. To use biff email notification, you must enable this service by running 'update-inetd --enable biff' after the package is installed. You may also need to modify the configuration of your mail transport agent to enable comsat notification.