Please trust me when I say, no you don't. I've had/have friends in prison that I've written. People I have known for 20 to 30 some years. I thought it would be a nice gesture to check in from time to time, let them know what was going on at home, etc... because very few people go to see them or write them.
Prison does a number on people. They are beyond bored, in a stressful situation, and this wears on the mind. Before you know it they start sending letters once a month, once every two weeks, once a week, and then every single day-respecting a reply on all of them. It's exhausting enough with people you know. Forget a stranger (and the added) danger!