biff

/bif/ , vt. [now rare] To notify someone of incoming mail. From the BSD
utility biff (1) , which was in turn named after a friendly dog who used to
chase frisbees in the halls at UCB while 4.2BSD was in development. There
was a legend that it had a habit of barking whenever the mailman came, but
the author of biff says this is not true. No relation to B1FF.