PDF Form Submission to Email Attachment

I have an existing industry PDF form. The potential customer would need to fill out and submit. Is there a best practice for providing an editable PDF that is then submitted as an email attachment? Or, is it best practice to send a form submission as a newly created PDF email attachment?

I would prefer not to keep the information from the form submission on the server due to the potential sensitive PI. I assume multiple plug-ins handle this problem, but I would greatly appreciate any suggestions on best practices or those plug-ins.