First off, you need to connect your event with an email marketing tool so you can capture those contact details. Once that's done, you'll be able to start setting up specific behavior-based actions.
​
We currently allow you to add actions to the following segments: 

Attendees: Registrants that joined their Session.

No Shows: Registrants that didn't show up for their Session.

You'll be able to assign a specific action to be performed on each of the above groups. Each integration will have different actions available which are listed in the dropdown.
​
For example, with MailChimp, you'll have the below actions available.
​ 
​Add to List

Remove From List