If you use a mailing list to reach some or all of the users/visitors on your web site on a regular basis, its subscribers are frequently called mailing list members. They have to subscribe and to give their explicit consent to receive automatic emails. You can approve mailing list members manually too, on the condition that the app that you use to manage the list permits this. As per the commonly accepted policies, a mailing list member should be able to unsubscribe whenever they like. You, being the mailing list administrator, can also remove members if they should not get email messages for some reason. The emails that each member receives will have only one single address in the "To" field, not the addresses of all the mailing list members.
