Hi,
Did you place [e2pdf-attachment id="1"]
shortcode to mail body? If yes and it still doesn’t generate PDF attachment: do you use any 3rd party mail plugins or 3rd party mail providers? If yes – try to disable it and check if it will be changed anything.
If it will not help we recommend to submit support ticket directly to us: https://e2pdf.com/support/contact
P.S. [e2pdf-view id="1"]
shortcode can be used only inside “Success Message”
P.P.S. Keep in mind also please that you need to do checks directly from “Frontend” page where form placed and not with “Preview” form functionality.