Hello there, @dcullen.
To stop receiving the carbon copy of the invoice you sent to your customer, you need to uncheck the default email message option under Account & Settings.
Here's how:
- Go to the Gear icon at the upper right corner of your screen.
- Click on the Account and Settings.

- Select Sales, then locate and select Messages.
- Please uncheck the box for Email me a copy at (your email).
- Click Save, then Done.

Once done, you can send your invoices to your customer without receiving carbon copy.
If the issue persists, let's consider troubleshooting your browser. While cache can speed up browsing, an excessive buildup can cause unexpected behaviors. A good starting point is to use a private browser, as it does not retain cache. If necessary, we can clear the cache.
Here's your future reference for managing invoice payments in QuickBooks: Record invoice payments.
Need help managing your books? Our QuickBooks Live Expert Assisted team has your back. We have dedicated bookkeepers ready to assist you in streamlining your accounting processes.
Feel free to use the Reply button below for any additional concerns about sending invoices to your customer.