The subscription accounts are created only when SMTP is used to receive email. They are not available when using POP3 accounts to retrieve email. They are also not available if the list is private. Each account is automatically named by LetterRip using the account name of the list. One account is used only for subscribing and the other account is used only for unsubscribing.
Any message sent to a subscription account controls the subscription and is otherwise ignored.
For example, any message sent to MyList-on is equivalent to a message sent to the requests account with a body or subject of subscribe MyList and would subscribe the sender to MyList. Similarly, any message sent to MyList-off is equivalent to a message sent to the requests account with the body or subject of unsubscribe MyList and would unsubscribe the sender from MyList. To subscribe to a digest version of a list, the subscriber must use the requests account. Using these accounts is optional. The requests account can still be used to control subscriptions.