Duplie allows volunteer coordinators to send out email campaigns to targeted users based on their group or activity.  You also have the ability to automatically send campaigns based on your pre-defined schedule.  The scheduled email campaigns will run on each scheduled date (weekly, monthly).  When triggered, it will query the targeted users and create the email campaign.  The schedule can be set to 'Auto Send' emails or 'Review' (default).  If 'Review', then an admin can go in and review the list/email content and send when they are ready.

To view campaigns and schedules, you can go to Site and Emails & Engagement.

Depending on your plan, you may be limited to the number of scheduled email campaigns you can setup.