- From your admin panel, navigate to Manage > Events.
- Click on the name of the event whose attendees you wish to contact.
- Click on the gear icon, and then on Message Attendees. This will bring you to the Email Campaigns tool.
- In the Recipients section, your event should be pre-filled in order to contact all attendees.
- Compose and send your message as usual.
The number of approximate recipients for this email will be equal to the number of event attendees.