Is there a way of setting up these types of parental controls for email (see details)?

Some day, when I finally rouse up the energy, I would like to set up an online math tutoring business. The main interface would be an interactive whiteboard, of which there are many available on the Web for little or no cost to use.

I thought it might be helpful if the students could email homework problems in advance of scheduled sessions. I am thinking of initially not charging for the time to go over the problems offline. Being able to review the problems beforehand would allow the online sessions go much more smoothly and would clearly be to the student’s advantage. I am assuming that there are at least some cases where the assignments do not have to be handed in the next day.

The problem is that parents might be hesitant to have their children correspond by email with a complete stranger. I know that I would be hesitant if I were the parent. Even if the parent does not have any problems with this, I would like some way of protecting myself from false accusations or misconstruals of things that I said. For the online sessions, I would allow and encourage parents to join the session and to review what is going on. It would be really helpful if there was a way of setting up an email account which could be logged into by both parent and student, but only the parent would have permission to delete correspondence. I suppose that all correspondence could go by way of the parent’s account, but this seems a bit awkward.

Any suggestions?