I did a postal writing course around 25 years ago. I paid all the fee up front and was sent a ring binder with my first lesson in it and several books on different aspects of writing. I managed to send in two assignments and they were sent back with full criticism. I did learn something from it in those early stages. I found the work hard at the time and stopped quite early. Looking back I found it to be very informative and very helpful. I wish I had stuck with it. I remember I had a very full life at the time and was too exhausted to continue but if you can spend a few hours on it every week you have to come out knowing more about writing than before you went in.