Sendmail
    Be able to send mail
    Be able to recieve mail
    Notice the permissions on /var/spool/mail
    Make a .forward file (what happens if the permissions are wrong?)
    Set the maximum recieved file size to 1KB
    Make an alias such that fred's mail goes to barney (or any such thing)

NFS
    Turn off root squashing
    Map the user fred -> barney (or any such thing)