Andy, I was testing the idea of sending our customers a PDF proof of their job request through an integrated setup. I decided against it but it may help you. We are a print shop and use each task or row as a job in the shop. Works beautifully.
What if you add a file cell column to your group, including the file you want to email in that cell, have an integration create an email to your customer using that file cell as an attachment? It may not be truly automatic but require some status change after the fact, to fire off the email with attachment. What I call “semi automatic”. Just an idea…