checkarray not running or emailing

[Leslie Rhorer <lesrhorer@xxxxxxx>]

    I have upgraded 2 of my servers to Debian Buster, and now neither 
one seems to be running checkarray automatically.  In addition, when I 
run checkarray manually, it isn't sending update emails on the status of 
the job.  Actually, I have never been able to figure out how checkarray 
runs.  One my older servers, there doesn't seem to be anything in 
/etc/crontab, /etc/cron.monthly, /etc/init.d/, /etc/mdadm/mdadm.conf, or 
/lib/systemd/system/ that would run checkarray.