Currently the students email their essays and I email the corrections. I'm hiring a teacher to take this position and I need to prevent any theft of clients -It is unlikely but I'd feel better if it were impossible. In the new system the students must be able to just email their essay. Thanks in advance
Well, it's certainly completely possible to build a system that would do what you're looking for, but I'd like to believe you can find something off-the-shelf that would accomplish it, since a custom system would definitely cost you more (e.g. thousands of dollars to get a decent system built by a reputable firm).
I'm guessing that the students are the clients in this setup?
One thing to watch out for is that if the student/client includes their name and/or contact information on their essay, then you (or the system) would ideally sanitize that information out of the essay before sending to the the teacher/employee.
I don't know a system that I'd recommend for this, but I hope that someone else is able to recommend something that you like.