Your request matters to us, nick-advancedit-. I can see how the functionality to change the email address when sending invoices would be beneficial to your business. I'm here to share some insights.
The default email received will show as quickbooks@notification.intuit.com. For now, we're unable to modify this when sending an invoice to your customer. I'd recommend sending a feature request directly to our Product Development team. This helps us improve your experience and the feature of the program.
Here's how:
Go to the Gear menu and then select Feedback.
Type in your feature request in the description box.
Additionally, I've added these articles that'll help you personalise your sales forms in QuickBooks Online. This way, you'll be able to add the info that matters most to your business: