I teach SAT and ACT. Your payrate depends on what you're trained for - LSAT and GRE courses are more difficult to teach, so you get more. MCAT is bank. But theres also a difference between private tutoring and classes. More is expected for private tutoring, but if you're good you can get about 3-4 an hour more than whatever you'd get for teaching a class in the equivalent topic.
I dont get paid for answering emails, but as I work with high schoolers, I dont get many anyways. Its not hard, but I'm kinda naturally a good teacher and did well on SAT's as it is. Cool thing is that we get paid for grading essays, so some days I sit on my ass in slippers and grade essays, at a dollar a essay. Doing that, if you're accurate and on top of it, you can go through 30 essays an hour... so $30 an hour.