Yes, you can send out a fully customized email to your clients after their appointments. You can set the exact number of minutes that after the appointment ends to send out the follow up automatically (even if you want it to go out weeks after the appointment).
To set up your follow up email, go to Set Up page -> Emails & Text Messages. Then from the list of messages, click on the "Appointment Follow Up"
Here you can customize the exact content of the email, and also activate the follow up email and set how long after each appointment it should be sent. Click on "Edit" against the default template on your account:
This option allows you to edit the content of the message and as well as when the system would send out the message:
Click "Save Templates" to save any changes made. You are also able to set up multiple email/sms follow up emails and you can adjust this based on the services that are booked, please click on the link below for more information:
https://help.flexbooker.com/en/articles/3854958-how-to-create-multiple-email-sms-templates-based-on-booked-service-s