[CentOS] sendmail and sudo

This is annoying. I ssh to a server, then, it doesn't matter if I su - or
sudo -s, I start a service (motion, if it matters), and when the service
sends an email, it's from me, not from root, or the user the service runs
as.

I've dumped my environment, I've just dumped service's environment. I've
set SUDO_USER to root, and SUDO_UID to 0, and restarted the service, and
still no joy.

My manager found this trick:
echo "To: user


help
" | sendmail -t

and the same thing happens.

Anyone else run into this? No relevant google hits so far.

        mark