[MM3-users] Posting replies vs starting a thread via email

In my tests where replies go to the list, when a person uses the email client? So far a reply to the original message and a reply to a reply to a reply all go in the same thread. Is this standard? Do I have to warn users not to have endless Re re re re?

And the other question is what happens if a user sends a message via email with a new subject? Does the list accept it as a new thread?

This should be one of my last big questions.

Thank you.

Paul