Binary package “biff” in ubuntu oneiric

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.