The email is a hoax. You can’t see the “firefall” in February as the email claimed. Firefall has been banned since 1968.
The email even used the Wikipedia picture of the ember-burning firefall to claim that it was sunlight on a waterfall at Glacier Point.
In reality, water has to be trucked up to the top of Glacier Point. Without Man, there is no water there at all, much less enough water for a waterfall.
Instead, the reality is that “firefall” was glowing embers from a nightly fire (until 1968).
Two different things here. There is a “firefall” that is not the burning embers pushed off Glacier Point. It’s the setting sun light playing off Horsetail Falls in late February: http://www.todayandtomorrow.net/2010/03/11/horsetail-firefall/