lucy24 - 7:18 pm on Jun 1, 2012 (gmt 0)
I'm going to go out on a limb and say you can't do it in html alone. You're looking at php. Not very complicated php, but still. Or, in the alternative, put the whole page in a directory with restricted access that uses a campus e-mail as part of the login.
What if your students send e-mail from their off-campus home computers?