2. Anyone who sends an e-mail to the list e-mail address gets their e-mail resent to the list. In other words, its not checking that subscribers only can send e-mail.
This email address isn't subscribed, so #2 must be right.
2. Anyone who sends an e-mail to the list e-mail address gets their e-mail resent to the list. In other words, its not checking that subscribers only can send e-mail.