Simplenews publishes and sends newsletters to lists of subscribers. Both anonymous and authenticated users can opt-in to different mailing lists.
Simplenews uses nodes for newsletter issues. Newsletter issues are grouped by a newsletter taxonomy term. Node type and vocabulary are selectable. A newsletter is send to all email addresses which are subscribed to the newsletter. Newsletter issues can be sent only once. Large mailings should be sent by cron to balance the mailserver load.
Simplenews adds elements to the newsletter node add/edit form to manage newsletter format and sending of the newsletter issue. A newsletter issue can be sent for test before sending officially.
Both anonymous and authenticated users can opt-in and opt-out to a newsletter. A confirmation message is sent to anonymous users when they (un)subscribe. Users can (un)subscribe using a form and a block. A subscription block is available for each newsletter offering a subscription form, a link to recent newsletters and RSS feed. Email addresses can also be imported and exported via the subscription administration pages.
For more information, see the online handbook entry for Simplenews.