If not, you'll be expected to keep track of the news page to see if you're missing anything. People are always free to leave the list. Maybe you're getting too much e-mail or maybe you just don't want to be on it. You won't be forced to stay longer than you want to. Unsubscribe instructions are in each letter.
All citizens are free to talk or discuss on the list.
That's what it's for. Any citizen can start a topic or add a comment to a discussion if they think they have something to say. It is frowned upon for people to send chain letters or advertisements to the list, and people who do so after receiving a warning will be taken off of the list. Likewise, citizens who insult other list members or send derogatory comments will be removed. The list is owned and moderated by the Emperor and not the government.