Simply put, if you write me, I might write back. I won't post any letters publicly unless 1) You give me permission or 2) You threaten me.
If you've given me permission to post a public answer, I'll still strip the name and return address off.
Feel free to write me; I like getting email. Emailing me directly will not add you to the newsletter mailing list.
If you subscribe to the newsletter, you agree to receive emails, about twice monthly. I will never resell or give away your email address.