NeetoCal allows you to run actions on the event of something. Let's say you want to send an email to the client when they don't show up to the meeting, here's how to do it:
Go to Admin Panel and click on Workflows
Add a new workflow, choose a name and description. In our example it will be "Send email to client when the booking is marked no-show"
Choose the event in When section and the action in Then section. Clicking the email link will open up an editor where you can type in the email.
Click on Save changes
Now whenever you mark a booking no-show, an email will be sent to the client.