8. Review and/or edit your Confirmation, Welcome and Farewell messages
The Confirmation Message is used only when someone uses your subscription form to sign up. It generates a message which they must reply to in order to prove they own that address.
The Welcome Message is sent when a reply is received to a Confirmation (above). It is used to verify that the person has been added and to welcome them. This is a good place to include details about how often to expect mailings, how to unsubscribe, etc. This welcome message is NOT sent to addresses which you import via the admin interface.
The Farewell Message is sent whenever someone unsubscribes via the unsub link.