For a quick glance here is a video - How to add attachments while sending emails to clients and providers
For the SMS/Email page under the Appointment category, prior to this change we could only send the email with text. With this new enhancement, now we can send attached files along with the email.
Note: Please make sure that the file size is less than 5MB.
To attach a file, click on Select files as highlighted in the above screenshot. From your PC, select the file you want to upload and click 'Open'.
You can add multiple attachments.