Quote:root is not in the sudoers file. This incident will be reported.

I've always wondered, why root is added by default to the sudoers file?

Also:

Quote:sudoers can log both successful and unsuccessful attempts (as well as errors) to
syslog(3), a log file, or both. By default, sudoers will log via syslog(3) but
this is changeable via the syslog and logfile Defaults setting

And in auth.log

It's your syslog implementation (for me here it's rsyslog) configuration that is forwarding it by email, it might not be default on all systems.