Yes, you can customize the email and message displayed to your clients once they submit a new meeting or contact request.
Navigate to Settings>Auto Client Messages
Enter your message in the Thank you message for contact requests and Thank you message for appointment requests and click on Save Changes.
You can also customize the auto reply email that is sent to your clients once they submit a new message or a meeting request as well as other automatic emails. Click here to learn how to edit the automatic email notifications.