How to send a notification based on user's answer.

I need to send 2 response emails based on the response to an RSVP form. If "YES" is selected then an email thanking them for attending and a different email if "NO" is selected say we are sorry they can't attend. Is this possible and if so how.

Create two email notifications, one that will contain the "Thank you" message, and the other one the "Sorry we can't attend" message: https://www.jotform.com/help/25-Setting-up-Email-Notifications 

Finally, create conditions to trigger the notifications based on the response, please check this guide: https://www.jotform.com/help/167-How-to-Send-Email-Based-on-User-s-Answer 

Let us know if you need more help, we will be glad to assist you.