Thanks for bringing this one to our attention, cdsJerry.
If you are making the edits in Outlook, then QuickBooks is unable to control that settings. I'd suggestreaching out to Outlook Support Team. What we can do is either set you up for webmail or edit your template in QuickBooks. Just follow the steps and details in these articles:
We can also add a new template and make modifications so you can use it when sending invoices and purchase orders to your customers. Let me show you how:
If the same thing happens, I'd recommend contacting our Technical Support Team. They'll pull up your account in a secure environment and check why it's using the default text when sending the transactions. Here's how:
Visit our QuickBooks Help Articles page for more insight s about managing your business in your software.
Feel free to update us after contacting our support as I want to make sure this is resolved for you. Just go back to this thread by leaving a comment. Take care always.