Does WHM6 automatically notify host and user when they reach 80% of their disk quota?

Or exhaust the same?

Or does it simply prevent further uploads when they reach their quota?

NOTE: Last question edited for clarification as I never intended nor hoped it would prevent further uploads at 80%.

If under Cpanel 6, you set it to notify host and user, it should do so but probably only at the time it check status once a day.

I guess once you exhaust 100% of the disk quota, you cannot upload any further and not at 80% or else you will be shortchanging your clients.