Hi, My invoices are sent from another e-mail address, my custoers don't recognize. Can I add an e-mail address and send the invoices from the new/added e-mail address?

I hope you're doing great today, @david224.

I want to share some clarifications regarding adding email addresses when sending invoices in QuickBooks Online.

The system only allows you to add and select multiple email addresses for the receiver of the invoice. In your case, you'll need to manually change the email to the one that's recognized by your customer when sending the invoice.

You can also add a message on the form indicating the reason for the email that you've used.

Please see the screenshots attached on where to add the message and to change the email:

For more details about creating and sending invoices together with customizing the form, please see this reference: Learn how to create and send invoices in QuickBooks Online.

On the other hand, I can see how helpful it would be to have the option to select your preferred email to be used when sending sales forms in QuickBooks Online.

Know that our developers are constantly working to develop the product by adding features that can cope with your business needs. I encourage you to send this feedback so this can be taken into consideration.

To do that:

1. Click on the Gear icon at the top.
2. Press on Feedback.
3. Share your feedback. 

I'm always here to assist you further if there's anything else that you need. Have a lovely day!