This class can be used to manage or newsletters mailing lists using a POP3 account. It can check a POP3 account for messages with request from users subscribe and unsubscribe from the list. The subscribers list is stored in a MySQL database table. It can also queue messages for delivery to the list subscribers using a remote SMTP server. The class also supports moderated lists and allowing and disallowing specify e-mail address from sending messages to a list.