For a forgotten password: <
http://n2.nabble.com/user/ForgotPassword.jtp>.
For a forgotten e-mail address: I'm not sure, but we could try this:
1. offer the URL of a message that you posted
2. from that message, I can reach your profile page then send you a message
3. I guess, the resulting message will be delivered to the Inbox of the address that is forgotten.