tl;dr
Sudo causes extra, useless alerts of "problem with defaults entries"
The environment
Ubuntu 16.04 Server LTS, sudo 1.8.16
The problem
Whenever a user (whether sssd-ad authenticated user, or local user, or root) uses sudo, it works. However, it also sends the administrator a useless email:
host1.example.com : Jun 6 14:40:44 : root : problem with defaults entries ; TTY=pts/2 ; PWD=/root ;
There are no defaults entries anymore! I removed them during my troubleshooting. I tried leaving them in. They were, by the way:
Defaults env_reset
Defaults mail_badpass
Defaults secure_path="/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin"
I cannot find the problem! I removed all my extra sudoers directives, and sudo (from root) still throws the error!
How do I make sudo stop sending me useless emails?