Attach Pdf's to Order Emails
To attach your customised pdf files to sales emails, go to Stores > Configuration > Sales > Sales Emails. Click into each email type and individually configure every email type you see below with the pdf documents you want to automatically attach.
Example: Invoice email settings
Standard Magento Settings
The first six settings are standard Magento settings - configure these as per normal.
Be sure to enable automatic sales emails.
Attach Order/Invoice/Shipment/Credit Memo as Pdf (v1.0.0+)
When set to “Yes”, your invoice/shipment/credit memo pdf document will be automatically attached to the order/invoice/shipment/credit memo email.
Attach Terms and Conditions (v1.0.0+)
When set to “Yes”, your Terms and Conditions (from Sales > Terms and Conditions) will automatically be attached to the email as a pdf.