How to set a task to poll the status of our Disk space

[aguang]

Hi, All,
May someone of you can help me on the below issue:
1. I am currently using insight Manager 7 and I would like it to send a disk space alert for our servers when the free space is lower than the disk threshold I set on the server.
2. I have set the disk threshold on other servers.
Below comes to my question: how do I need to do inside the Insight Manager so it will give me an E-mail Notice when the free space is lower than the disk threshold I set.

Thanks in advance
Best Regards
Aguang