I don't accept e-mailed final assignments for the exact same reason as kataplexis; one semester, five of my students wanted to e-mail the final essay on which their whole grade depended, didn't send it, and then claimed it must have gone missing in the Internet ether. That led to grade challenges when I failed them and a whole bunch of irritation and bad shit. The same semester, one student claimed a paper was five pages long on her computer, and she didn't know what could have happened to only make it three pages long in Microsoft Word when she e-mailed it to me! Oooh, the Internet gnomes must have magically changed her font!

I can see why people like the convenience, and for some people it's a necessity, but too often students think "convenience" means "loophole."