You can schedule emails that go out automatically to ticket holders, like a reminder the day before or a thank you after the event.

From your event dashboard, open the campaigns section and choose to schedule an email. Pick when it goes out (number of days or hours before or after the event) and write your message.

From the campaign page, clicking View Content shows you the email in read only mode. To make changes, click Edit on the campaign itself.

Send yourself a test email from the editor before saving the schedule, so you know exactly what your attendees will receive.