Clever with the binder clips! Thank you.

The Stamps.com SDC-3610 labels don't have a physical return receipt but instead allow for electronic return receipt. They're easy to save once the email comes through. I put the client name in the "first name" field and the form in "last name." Perhaps it's wonky, but when the receipt confirmations come back, "Dear Company XYZ 2021 1120-S," it makes it simpler to identify what mailing it pertains to.