Logdigest, run by cron at night, greps through system log files
(/var/log/messages, /var/log/mail, etc.) to find "interesting" content.

Lines matching the regular expressions in /etc/logdigest/ignore are simply
ignored. More expressions can be added to %{_sysconfdir}/logdigest/ignore.local.
See /etc/logdigest/config for some general settings.

The results are mailed to the sysadmin daily.