Attaching PDF/ Proof of delivery to invoice

I am looking to use this invoicing plugin for a courier company, looks great so far.

The two questions that I have, however, are both quite similar.

I have added the PDF plugin, and am wondering if there is a way for the PDF to be included as an attachment when i send an invoice to a customer, as yet, the email only contains a link, I feel it wold be more professional looking if the invoice was actually included as an attachment to be opened instantly.

Also, as I am using it for a courier, I would like to be able to include Proof of Delivery.

Ideally I would like to also be able to add this as an attachment.

I have also downloaded the CRM plugin, to allow customers to view all their activity, I would also like the PDF and Proof of Delivery to be accessible here.

Is this possible to do? or will it be going forwards?