Hello, @CanadianEh.

When sending your transactions from QuickBooks, you can see a preview of the actual your client would receive. Also, you can set up a default email for that will be use every time you email a sales form from QuickBooks. I can guide you on how to do it.

1. Go to the Gear icon.
2. Choose Account and Settings.
3. From the Sales menu, locate the Messages section.
4. Select the Sales form you'd like to set.
5. Enter the default email message.
6. Click Save. 

Lastly, make sure to set your QuickBooks to attached a copy of the actual PDF file of the sales form. Here's how:

1. Go to the Gear icon.
2. Choose Account and Settings.
3. Select Sales.
4. From the Online delivery section, make sure the PDF Attached is ticked.
5. Click Save. Then, Done.

This way, they can see the actual copy of the invoice.

I'm adding these articles to help you manage your sale forms in QuickBooks:

• Delivery Errors when trying to email a sales form
• How to set up or change customer messages
• Customise invoices, quotes, and sales receipts in QuickBooks Online. 

Keep me posted if you have other questions or concerns. I'm always here to help.