The mailinglist plugin offers a website a way to send emails to a group of people who signed up to a certain mailing list.
The system offers a way to enter a mailing list email and the Snap! system converts that special email address in one email per user who registered. Although it would be possible to have the list of emails defined in your mail system instead, by having it in Snap! directly allows us to enforce emailing policies defined on the Snap! Websites. For example, a user could ask to receive one email per week maximum with a digest of whatever was sent to him within that week. Another may choose to never receive emails, he can checks his messages when he comes to the website and otherwise, no spam in his mailbox! This requires us to know exactly who has to receive this and that email.
The mailinglist plugin offers ways for users to subscribe or unsubscribe for a mailing list and ways for the administrator to add/remove users in batch.