5.7 Positive Persuasive Letter
Counterargument
Here is an idea for counterargument in your letter. As it is strangers who is your audience, it is harder to predict their questions. A possibility is that they might be having a difficult day, so you could address that.
E.g. On the day this letter finds you, you might be having a difficult day. It might be hard to think positive, but you can do it. Helen Keller once said, "Keep your face to the sunshine and you cannot see the shadows