If you want to see if an email or notification has been sent to your guest, go to Booking view page ( Bookings -> All Bookings -> click on the name of the guest). Go to Activities section. There, you can see all the emails and notifications that have been sent to your guest. If you click on the title, you’ll see the details of the email or notification.
In addition, you can see other tasks that have been created for that booking.