You can send a drip campaign to past attendees from any of your pages. This also includes pages from other products including RegFox, RedPodium or GivingFuel.
Navigate to Email Center → Email Automation from the top menu
Click the "Create New Automation" button
Title your automation using the Automation Name field. This will only be visible to you.
Select "Past Registrants" and click in the field. You can browse or search for a specific page.
You can add one page or multiple pages by selecting multiple pages.
Click "Create Automation" and the number of recipients and pages you selected will be listed on the page.