Command explanations
cp limits login.access and others: These files
were not installed during the installation of the package so we copy
them manually as those files are used to configure authentication
details on the system.
sed "s|/var/spool/mail|/var/mail|" login.defs.linux >
/etc/login.defs: /var/spool/mail is the old location of the
user mailboxes. The location that is used nowadays is /var/mail.