Stealthseminar's Email Reminders can be Enabled or Disabled at the Scheduling section in your webinar event (as shown below) a default message is setup to send when enabled.

Customizing them is an option; You can preview default messages in the Customize section. If you want to customize them there you can, article links how to are provided below.

Our system will send 3 default type reminder emails based on the Registrant's schedule choice:

Registration Confirmation Email

60-Minute Email Reminder

5-Minute Email Reminder

You can customize the emails & even add personalized pics for registrants at them.