Translation of Hintertür

From time to time I listen to my old CD collection. However, most of the CD boxes, meaning the covers, are so full of dust that one can hardly see the image. Taste changes with the age, that is known.
I wrote you an email. Is this still your address? Please respond if so. Anything goes. I am with May tomorrow. I hope that is OK with you... You're checking out the new Ford, I heard. A great car.
We found an password solution to enable teachers and their students to work with your lessons. These teachers would need to enter the password of the lessons and could then continue to use them.