Emails to everyone signed up for a class in scheduling

I have a client with several classes available on her scheduling platform. She would like to know if it's possible to easily send an email to everyone who has signed up for a class, in case of any updates.

For example, let's say that Kathy's 9:00 class has been delayed 15 minutes, or that Steve will be subbing in for Kathy at 4:00. Is there a way to send one email to all those people with that update?