Incorrect password.
Use {{FIRST_NAME}} anywhere you want a personal greeting, and {{UNSUBSCRIBE_URL}} in the footer — every subscriber gets their own working unsubscribe link automatically. The send will refuse to go out without an unsubscribe placeholder somewhere in the body.
This will send to … real subscribers right now. There's no undo. Sure?
This is roughly how it'll render in an inbox. {{FIRST_NAME}} shows as "there" and the unsubscribe link is a placeholder here — both get filled in per-subscriber on actual send.