Does mdadm monitor and email automatically?

I have set up mdadm raid 1 on 2 disks fine and have got the test emails working using

mdadm --monitor --test --oneshot --scan

My config is at /etc/config/mdadm and I have run /etc/init.d/mdadm enable and on reboot everything works as expected. Great.

But what I haven’t worked out is whether I need to specify anything in the config so that I will get emailed if anything goes wrong with a disk. ie. in the config do I have to specify MONITOR anywhere or is it already assumed?

(or) Is there another method like running a second mdadm process with the --monitor flag that is required?