Hi, I have an issue which was reported by another user as well regarding the attachement of PDF's in e-mails:

ISSUE: There is no pdf invoices/quotes currently being attached to mail.

I currently have the following configuration:
1: Directory called pdfinvoices in public_html (this is the root of my joomla install), permissions set to 755.
2: In Invoice Manager configuration. Attach PDF Invoice in email - YES.
3: Extracted the dompdf.zip to public_html/components/com_invoices/helpers

Download PDF button working as expected. PDF is created correctly. Sending emails do not include the PDF as attachement.

thanks for the support
Dino