All digital forms in Cojilio are a "submit back" option.
In this case, you have 2 options:
Option 1: Form in Cojilio
Make your form "required before appointment > 7 days" so clients receive it 7 days before their appointment, for example.
Make the entire form the information, and the end of the form is a checkbox "I have read & understand all the above info" is the checkbox description.
This way, you receive the confirmation that they have read & agreed to all of the information above.
Option 2: Email Marketing in another system
If you don't want this to be a form in Cojilio, you can create an email campaign in a software like MailChimp, and set a trigger based on a tag.
To use MailChimp, export your client list from Cojilio > Import into MailChimp > Create an automated Email Campaign > Set the campaign to trigger upon being tagged > Send to clients by tagging them "Service" for example.
For more information on MailChimp Email Campaign Software: https://mailchimp.com/