I have no experience with mail labels. However, the printer handles all special label printing jobs in my practice cleanly and flawlessly. It has just succeeded in printing COVID vaccination book labels in the standard Avery format L4731REV-25 with 189 labels per A4 page, size 10 x 25 mm in the smallest font size 5 in impressive quality with precise adherence to the print position! So the question is rather: is your writing program able to print the format of the mail labels?

Can only confirm Biberstall, there is hardly any lack of printers