Good morning, @degmusic.
Let's look at the Shipping Manager in your QuickBooks Desktop to edit the printing for your envelopes.
Depending on what type of shipping you use (UPS, USPS, FedEx), you can go into each one to edit the labels. You can review this Community Article for detailed steps on how to do this with ease: Configure your Settings for Printing in Shipping Manager.
Once you've edited the Return Shipping Address, then these settings will be saved and used for printing. If you need further assistance, please don't hesitate and reach back out to me! I'm just a Reply away. Have a beautiful day.
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