Messages & comments

1. Can I move items from one Basecamp project to another?
2. Can I email a message to Basecamp Classic?
3. How can we format (bold, bullets, italics, etc.) our messages or comments?
4. How can I stop receiving email notifications?
5. Can I post HTML/PHP/JavaScript into a message?
6. I'm no longer receiving email notifications from Basecamp. What's going on?
7. Can I add comments or files on to-dos?
8. How does the privacy setting work in Basecamp?
9. Can I add someone to the email notification list after a message has been posted?
10. How do email notifications work?
11. Can I reply to messages via email?
12. How do I attach files to messages?
13. Can I add comments or files on milestones?
14. How can I change global categories for files or messages?
15. What does "associate with a milestone" mean on a message?
16. What's the difference between green and grey icons in List view?
17. I keep getting a delivery failure when I try to send a comment via email. What’s wrong?
18. I changed the global categories, but they didn't change inside my project. Why?