biff — be notified if mail arrives and who it is from

su(1), and biff don't seem to get on too well. This is probably due to the tty still being owned  by  the
       person  using  su.  This  can  result  in “Permissiondenied” messages when attempting to change the biff
       status of your session.

       Please report bugs to netbug@ftp.uk.linux.org including diffs/patches, compiler error logs or as complete
       a bug report as is possible.

Linux NetKit (0.17-pre-20000412)                  July 31, 1999                                          BIFF(1)

Biff  informs  the  system  whether you want to be notified when mail arrives during the current terminal
       session.

       Options supported by biff:

       n     Disables notification.

       y     Enables notification.

       When mail notification is enabled, the header and first few lines of the message will be printed on  your
       screen  whenever mail arrives.  A “biffy” command is often included in the file .login or .profile to be
       executed at each login.

       Biff operates asynchronously via the comsat(8) service. If that service is not enabled, biff will not  do
       anything.  In  that  case,  or  for  synchronous notification, use the MAIL variable of sh(1) or the mail
       variable of csh(1).

       The biff command appeared in 4.0BSD.

       biff — be notified if mail arrives and who it is from

csh(1), mail(1), sh(1), comsat(8)

biff [ny]