Is it possible to change the customized email address for forwarding images of receipt once it has been confirmed? I know it says you can’t, but is it possible?

What you know is right, harvesthomeconst.

Once you claim an email address, you can't change it. You might want to see the detailed information in these articles: 

• Email receipts and bills to QuickBooks Online
• Capture and categorize expense receipts and bills in QuickBooks Online

You can also visit our Intuit Developer page regarding this matter. They might have a way to bypass this limitation or suggest other third-party application to do this.

1. Go to this link and log in to your Intuit account: https://help.developer.intuit.com/s/.
2. Select QuickBooks Online under What do you need help with?.
3. Click Ask a Question and enter the details of your concern.
4. Select Ask.

We'll be right here if you need anything else.